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Sample records for brain ambiguous representations

  1. Ambiguous science and the visual representation of the real

    Science.gov (United States)

    Newbold, Curtis Robert

    The emergence of visual media as prominent and even expected forms of communication in nearly all disciplines, including those scientific, has raised new questions about how the art and science of communication epistemologically affect the interpretation of scientific phenomena. In this dissertation I explore how the influence of aesthetics in visual representations of science inevitably creates ambiguous meanings. As a means to improve visual literacy in the sciences, I call awareness to the ubiquity of visual ambiguity and its importance and relevance in scientific discourse. To do this, I conduct a literature review that spans interdisciplinary research in communication, science, art, and rhetoric. Furthermore, I create a paradoxically ambiguous taxonomy, which functions to exploit the nuances of visual ambiguities and their role in scientific communication. I then extrapolate the taxonomy of visual ambiguity and from it develop an ambiguous, rhetorical heuristic, the Tetradic Model of Visual Ambiguity. The Tetradic Model is applied to a case example of a scientific image as a demonstration of how scientific communicators may increase their awareness of the epistemological effects of ambiguity in the visual representations of science. I conclude by demonstrating how scientific communicators may make productive use of visual ambiguity, even in communications of objective science, and I argue how doing so strengthens scientific communicators' visual literacy skills and their ability to communicate more ethically and effectively.

  2. Disambiguation of ambiguous figures in the brain

    Directory of Open Access Journals (Sweden)

    Tomohiro eIshizu

    2013-08-01

    Full Text Available Disambiguation refers to the ability to interpret ambiguous information in a sensible way, which is important in an ever-changing external environment. Disambiguation occurs when prior knowledge is given before an ambiguous stimulus is presented. For example, labeling a series of meaningless blobs as the human body can change the observer’s perception. The aim of this experiment was to study the neural circuitry underlying disambiguation caused by prior knowledge. We presented to participants a series of meaningless blobs with different contextual information. As participants performed this task, we used magnetoencephalography to map the brain areas that were activated when participants perceived blobs as a human body. The participants were presented identical sets of blob stimuli, and were instructed that a human body would appear more frequently in the high body condition than in the low body condition. We found the blob stimuli were more frequently perceived as the human body when they were presented in the high body condition. Such contextual modulation correlated with activity in the extrastriate body area (EBA and the inferior frontal gyrus (IFG. Furthermore, we observed that IFG activation preceded EBA activation. These findings suggest that top-down processing in the IFG plays a role in disambiguating ambiguous information and modifying an individual’s perceptions.

  3. Representation and productive ambiguity in mathematics and the sciences

    CERN Document Server

    Grosholz, Emily R

    2007-01-01

    Emily Grosholz offers an original investigation of demonstration in mathematics and science, examining how it works and why it is persuasive. Focusing on geometrical demonstration, she shows the roles that representation and ambiguity play in mathematical discovery. She presents a wide range of case studies in mechanics, topology, algebra, logic, and chemistry, from ancient Greece to the present day, but focusing particularly on the seventeenth and twentieth centuries. Anyone interested in how mathematics works will find this a stimulating read.

  4. Effect of Representational Distance between Meanings on Recognition of Ambiguous Spoken Words

    OpenAIRE

    Mirman, Daniel; Strauss, Ted J.; Dixon, James A.; Magnuson, James S.

    2009-01-01

    Previous research indicates that mental representations of word meanings are distributed along both semantic and syntactic dimensions such that nouns and verbs are relatively distinct from one another. Two experiments examined the effect of representational distance between meanings on recognition of ambiguous spoken words by comparing recognition of unambiguous words, noun-verb homonyms, and noun-noun homonyms. In Experiment 1, auditory lexical decision was fastest for unambiguous words, slo...

  5. Brain responses to nouns, verbs and class-ambiguous words in context.

    Science.gov (United States)

    Federmeier, K D; Segal, J B; Lombrozo, T; Kutas, M

    2000-12-01

    Recent neuropsychological and imaging data have implicated different brain networks in the processing of different word classes, nouns being linked primarily to posterior, visual object-processing regions and verbs to frontal, motor-processing areas. However, as most of these studies have examined words in isolation, the consequences of such anatomically based representational differences, if any, for the processing of these items in sentences remains unclear. Additionally, in some languages many words (e.g. 'drink') are class-ambiguous, i.e. they can play either role depending on context, and it is not yet known how the brain stores and uses information associated with such lexical items in context. We examined these issues by recording event-related potentials (ERPs) in response to unambiguous nouns (e.g. 'beer'), unambiguous verbs (e. g. 'eat'), class-ambiguous words and pseudowords used as nouns or verbs within two types of minimally contrastive sentence contexts: noun-predicting (e.g. 'John wanted THE [target] but.') and verb-predicting ('John wanted TO [target] but.'). Our results indicate that the nature of neural processing for nouns and verbs is a function of both the type of stimulus and the role it is playing. Even when the context completely specifies their role, word class-ambiguous items differ from unambiguous ones over frontal regions by approximately 150 ms. Moreover, whereas pseudowords elicit larger N400s when used as verbs than when used as nouns, unambiguous nouns and ambiguous words used as nouns elicit more frontocentral negativity than unambiguous verbs and ambiguous words used as verbs, respectively. Additionally, unambiguous verbs elicit a left-lateralized, anterior positivity (approximately 200 ms) not observed for any other stimulus type, though only when these items are used appropriately as verbs (i.e. in verb-predicting contexts). In summary, the pattern of neural activity observed in response to lexical items depends on their general

  6. Self-Representation and Brain Development

    Science.gov (United States)

    Lewis, Michael; Carmody, Dennis P.

    2008-01-01

    This study examined the relation between self-representation and brain development in infants and young children. Self-representation was assessed by mirror recognition, personal pronoun use, and pretend play. Structural brain images were obtained from magnetic resonance imaging (MRI). Brain development was assessed by a quantitative measure of…

  7. Effects of representational distance between meanings on the neural correlates of semantic ambiguity.

    Science.gov (United States)

    Grindrod, Christopher M; Garnett, Emily O; Malyutina, Svetlana; den Ouden, Dirk B

    2014-12-01

    Psycholinguistic research demonstrates that representational distance between meanings influences recognition of ambiguous words. Our goal was to investigate whether the neural correlates of ambiguity are also modulated by representational distance as a function of syntactic similarity (i.e., grammatical class) and meaning dominance. In an event-related fMRI experiment, participants completed a visual lexical decision task that included balanced and unbalanced noun-noun and noun-verb homonyms, unambiguous words, and nonwords. Syntactic similarity effects were observed in left inferior frontal regions, with greater activation for noun-verb than noun-noun homonyms. Meaning dominance effects were observed in left middle and superior temporal regions, with greater activation for balanced than unbalanced homonyms. These findings indicate that the behavioral cost associated with processing ambiguous word meanings, modulated by syntactic similarity and meaning dominance, is reflected in the neural systems underlying ambiguity processing, as frontal and temporal regions are recruited by increased competition as a function of representational distance. PMID:25463814

  8. Brain Image Representation and Rendering: A Survey

    Directory of Open Access Journals (Sweden)

    Mudassar Raza

    2012-09-01

    Full Text Available Brain image representation and rendering processes are basically used for evaluation, development and investigation consent experimental examination and formation of brain images of a variety of modalities that includes the major brain types like MEG, EEG, PET, MRI, CT or microscopy. So, there is a need to conduct a study to review the existing work in this area. This paper provides a review of different existing techniques and methods regarding the brain image representation and rendering. Image Rendering is the method of generating an image by means of a model, through computer programs. The basic purpose of brain image representation and rendering processes is to analyze the brain images precisely in order to effectively diagnose and examine the diseases and problems. The basic objective of this study is to evaluate and discuss different techniques and approaches proposed in order to handle different brain imaging types. The paper provides a short overview of different methods, in the form of advantages and limitations, presented in the prospect of brain image representation and rendering along with their sub categories proposed by different authors.

  9. Quantum cognition based on an ambiguous representation derived from a rough set approximation.

    Science.gov (United States)

    Gunji, Yukio-Pegio; Sonoda, Kohei; Basios, Vasileios

    2016-03-01

    Over the last years, in a series papers by Arecchi and others, a model for the cognitive processes involved in decision making has been proposed and investigated. The key element of this model is the expression of apprehension and judgment, basic cognitive process of decision making, as an inverse Bayes inference classifying the information content of neuron spike trains. It has been shown that for successive plural stimuli this inference, equipped with basic non-algorithmic jumps, is affected by quantum-like characteristics. We show here that such a decision making process is related consistently with an ambiguous representation by an observer within a universe of discourse. In our work the ambiguous representation of an object or a stimuli is defined as a pair of maps from objects of a set to their representations, where these two maps are interrelated in a particular structure. The a priori and a posteriori hypotheses in Bayes inference are replaced by the upper and lower approximations, correspondingly, for the initial data sets that are derived with respect to each map. Upper and lower approximations herein are defined in the context of "rough set" analysis. The inverse Bayes inference is implemented by the lower approximations with respect to the one map and for the upper approximation with respect to the other map for a given data set. We show further that, due to the particular structural relation between the two maps, the logical structure of such combined approximations can only be expressed as an orthomodular lattice and therefore can be represented by a quantum rather than a Boolean logic. To our knowledge, this is the first investigation aiming to reveal the concrete logic structure of inverse Bayes inference in cognitive processes. PMID:26861118

  10. The bilingual brain: cerebral representation of languages.

    Science.gov (United States)

    Fabbro, F

    2001-11-01

    The present article deals with theoretical and experimental aspects of language representation in the multilingual brain. Two general approaches were adopted in the study of the bilingual brain. The study of bilingual aphasics allows us to describe dissociations and double dissociations between the different subcomponents of the various languages. Furthermore, symptoms peculiar to bilingual aphasia were reported (pathological mixing and switching and translations disorders) which allowed the correlation of some abilities specific to bilinguals with particular neurofunctional systems. Another approach to the study of the bilingual brain is of the experimental type, such as electrophysiological investigations (electrocorticostimulation during brain surgery and event-related potentials) and functional neuroanatomy studies (positron emission tomography and functional magnetic resonance imaging). Functional neuroanatomy studies investigated the brain representation of languages when processing lexical and syntactic stimuli and short stories. Neurophysiologic and neuroimaging studies evidenced a similar cerebral representation of L1 and L2 lexicons both in early and late bilinguals. The representation of grammatical aspects of languages seems to be different between the two languages if L2 is acquired after the age of 7, with automatic processes and correctness being lower than those of the native language. These results are in line with a greater representation of the two lexicons in the declarative memory systems, whereas morphosyntactic aspects may be organized in different systems according to the acquisition vs learning modality.

  11. Enhancing lexical ambiguity resolution by brain polarization of the right posterior superior temporal sulcus.

    Science.gov (United States)

    Peretz, Yael; Lavidor, Michal

    2013-04-01

    Previous studies have reported a hemispheric asymmetry in processing dominant (e.g., paper) and subordinate (e.g., farmer) associations of ambiguous words (pen). Here we applied sham and anodal Transcranial Direct Current Stimulation (tDCS) over Wernicke's area and its right homologue to test whether we can modulate the selective hemispheric expertise in processing lexical ambiguity. Ambiguous prime words were presented followed by target words that could be associated to the dominant or subordinate meaning of the prime in a semantic relatedness task. Anodal stimulation of the right Wernicke's area significantly decreased response time (RTs) to subordinate but not dominant associations compared to sham stimulation. There was also a complementary trend of faster responses to dominant associations following anodal stimulation of Wernicke's area. The results support brain asymmetry in processing lexical ambiguity and show that tDCS can enhance complex language processing even in a sample of highly literate individuals. PMID:22513342

  12. When Does the Brain Distinguish between Genuine and Ambiguous Smiles? An ERP Study

    Science.gov (United States)

    Calvo, Manuel G.; Marrero, Hipolito; Beltran, David

    2013-01-01

    Event-related brain potentials (ERPs) were recorded to assess the processing time course of ambiguous facial expressions with a smiling mouth but neutral, fearful, or angry eyes, in comparison with genuinely happy faces (a smile and happy eyes) and non-happy faces (neutral, fearful, or angry mouth and eyes). Participants judged whether the faces…

  13. Global motion coherence can influence the representation of ambiguous local motion

    OpenAIRE

    Scarfe, P.; Johnston, A.

    2011-01-01

    Early cortical responses to visual motion are inherently ambiguous as to underlying motion in the world. This ambiguity derives from the fact that directionally selective cells in early visual areas, such as V1, can predominantly signal only 1D motion orthogonal to image contours spanning their small, spatially localized, receptive fields. One way in which local ambiguity could be overcome is by integrating motion signals over orientation and space. Here, we show that the direction of an afte...

  14. Semantic Ambiguity and Perceived Ambiguity

    CERN Document Server

    Poesio, M

    1995-01-01

    I explore some of the issues that arise when trying to establish a connection between the underspecification hypothesis pursued in the NLP literature and work on ambiguity in semantics and in the psychological literature. A theory of underspecification is developed `from the first principles', i.e., starting from a definition of what it means for a sentence to be semantically ambiguous and from what we know about the way humans deal with ambiguity. An underspecified language is specified as the translation language of a grammar covering sentences that display three classes of semantic ambiguity: lexical ambiguity, scopal ambiguity, and referential ambiguity. The expressions of this language denote sets of senses. A formalization of defeasible reasoning with underspecified representations is presented, based on Default Logic. Some issues to be confronted by such a formalization are discussed.

  15. How Nation-States Hit Europe Ambiguity and Representation in the European Union

    Directory of Open Access Journals (Sweden)

    Jarle Trondal

    2003-04-01

    Full Text Available Most studies of the EU and its member-states are concerned with how processes of European integration hit the member-states. This article shifts emphasis from this top-down towards a bottom-up approach and asks whether and how differences in domestic institutional constellations shape the representational roles of member-state officials when carrying out representational tasks in the EU Council of Ministers. The key objective of this study is to build a conceptual framework that renders intelligible the domestic origins of representational roles among domestic officials attending EU institutions. For this we draw on theories of political representation, institutional theories and the literature on how member-states adapt to European integration. Our primary argument is that role perceptions are considerably conditioned by actors domestic institutional embeddedness. This argument is substantiated by an illustrative comparison of Belgian and Swedish officials attending working groups within the Council of Ministers.

  16. Perceptual Representation as a Mechanism of Lexical Ambiguity Resolution: An Investigation of Span and Processing Time

    Science.gov (United States)

    Madden, Carol J.; Zwaan, Rolf A.

    2006-01-01

    In 2 experiments, the authors investigated the ability of high- and low-span comprehenders to construe subtle shades of meaning through perceptual representation. High- and low-span comprehenders responded to pictures that either matched or mismatched a target object's shape as implied by the preceding sentence context. At 750 ms after hearing the…

  17. Ambiguous bodies in motion : representations of female identity in contemporary screendance

    OpenAIRE

    Sprague, Terry

    2010-01-01

    The female body is one of the most heavily culturally coded signifiers both historically and in visual cultures around the world. At a time when visual media technologies are increasingly becoming integral to our daily lives, and emergent art and visual technology forms such as screendance circulate along global pathways with other media objects, to what extent can screendance resist, or even transform, the pervasive commercial representations of, and messages about, the female body? Drawing ...

  18. Stimulating the brain's language network: syntactic ambiguity resolution after TMS to the inferior frontal gyrus and middle temporal gyrus.

    Science.gov (United States)

    Acheson, Daniel J; Hagoort, Peter

    2013-10-01

    The posterior middle temporal gyrus (MTG) and inferior frontal gyrus (IFG) are two critical nodes of the brain's language network. Previous neuroimaging evidence has supported a dissociation in language comprehension in which parts of the MTG are involved in the retrieval of lexical syntactic information and the IFG in unification operations that maintain, select, and integrate multiple sources of information over time. In the present investigation, we tested for causal evidence of this dissociation by modulating activity in IFG and MTG using an offline TMS procedure: continuous theta-burst stimulation. Lexical-syntactic retrieval was manipulated by using sentences with and without a temporarily word-class (noun/verb) ambiguity (e.g., run). In one group of participants, TMS was applied to the IFG and MTG, and in a control group, no TMS was applied. Eye movements were recorded and quantified at two critical sentence regions: a temporarily ambiguous region and a disambiguating region. Results show that stimulation of the IFG led to a modulation of the ambiguity effect (ambiguous-unambiguous) at the disambiguating sentence region in three measures: first fixation durations, total reading times, and regressive eye movements into the region. Both IFG and MTG stimulation modulated the ambiguity effect for total reading times in the temporarily ambiguous sentence region relative to the control group. The current results demonstrate that an offline repetitive TMS protocol can have influences at a different point in time during online processing and provide causal evidence for IFG involvement in unification operations during sentence comprehension.

  19. Quantum processes, space-time representation and brain dynamics

    CERN Document Server

    Roy, Sisir; Roy, Sisir; Kafatos, Menas

    2003-01-01

    The recent controversy of applicability of quantum formalism to brain dynamics has been critically analysed. The prerequisites for any type of quantum formalism or quantum field theory is to investigate whether the anatomical structure of brain permits any kind of smooth geometric notion like Hilbert structure or four dimensional Minkowskian structure for quantum field theory. The present understanding of brain function clearly denies any kind of space-time representation in Minkowskian sense. However, three dimensional space and one time can be assigned to the neuromanifold and the concept of probabilistic geometry is shown to be appropriate framework to understand the brain dynamics. The possibility of quantum structure is also discussed in this framework.

  20. Ambiguous Proximity Distribution

    OpenAIRE

    Wang, Quanquan; Li, Yongping

    2014-01-01

    Proximity Distribution Kernel is an effective method for bag-of-featues based image representation. In this paper, we investigate the soft assignment of visual words to image features for proximity distribution. Visual word contribution function is proposed to model ambiguous proximity distributions. Three ambiguous proximity distributions is developed by three ambiguous contribution functions. The experiments are conducted on both classification and retrieval of medical image data sets. The ...

  1. Frequency representation within the human brain: Stability versus plasticity

    OpenAIRE

    Lim, Hubert H.; Minoo Lenarz; Gert Joseph; Thomas Lenarz

    2013-01-01

    A topographical representation for frequency has been identified throughout the auditory brain in animals but with limited evidence in humans. Using a midbrain implant, we identified an ordering of pitch percepts for electrical stimulation of sites across the human inferior colliculus (IC) that was consistent with the IC tonotopy shown in animals. Low pitches were perceived by the subject for stimulation of superficial IC sites while higher pitches were perceived for stimulation of deeper sit...

  2. Distributed representations in memory: insights from functional brain imaging.

    Science.gov (United States)

    Rissman, Jesse; Wagner, Anthony D

    2012-01-01

    Forging new memories for facts and events, holding critical details in mind on a moment-to-moment basis, and retrieving knowledge in the service of current goals all depend on a complex interplay between neural ensembles throughout the brain. Over the past decade, researchers have increasingly utilized powerful analytical tools (e.g., multivoxel pattern analysis) to decode the information represented within distributed functional magnetic resonance imaging activity patterns. In this review, we discuss how these methods can sensitively index neural representations of perceptual and semantic content and how leverage on the engagement of distributed representations provides unique insights into distinct aspects of memory-guided behavior. We emphasize that, in addition to characterizing the contents of memories, analyses of distributed patterns shed light on the processes that influence how information is encoded, maintained, or retrieved, and thus inform memory theory. We conclude by highlighting open questions about memory that can be addressed through distributed pattern analyses.

  3. Abstract representations of associated emotions in the human brain.

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    Kim, Junsuk; Schultz, Johannes; Rohe, Tim; Wallraven, Christian; Lee, Seong-Whan; Bülthoff, Heinrich H

    2015-04-01

    Emotions can be aroused by various kinds of stimulus modalities. Recent neuroimaging studies indicate that several brain regions represent emotions at an abstract level, i.e., independently from the sensory cues from which they are perceived (e.g., face, body, or voice stimuli). If emotions are indeed represented at such an abstract level, then these abstract representations should also be activated by the memory of an emotional event. We tested this hypothesis by asking human participants to learn associations between emotional stimuli (videos of faces or bodies) and non-emotional stimuli (fractals). After successful learning, fMRI signals were recorded during the presentations of emotional stimuli and emotion-associated fractals. We tested whether emotions could be decoded from fMRI signals evoked by the fractal stimuli using a classifier trained on the responses to the emotional stimuli (and vice versa). This was implemented as a whole-brain searchlight, multivoxel activation pattern analysis, which revealed successful emotion decoding in four brain regions: posterior cingulate cortex (PCC), precuneus, MPFC, and angular gyrus. The same analysis run only on responses to emotional stimuli revealed clusters in PCC, precuneus, and MPFC. Multidimensional scaling analysis of the activation patterns revealed clear clustering of responses by emotion across stimulus types. Our results suggest that PCC, precuneus, and MPFC contain representations of emotions that can be evoked by stimuli that carry emotional information themselves or by stimuli that evoke memories of emotional stimuli, while angular gyrus is more likely to take part in emotional memory retrieval. PMID:25855179

  4. Brain correlates of mathematical competence in processing mathematical representations

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    Roland H. Grabner

    2011-11-01

    Full Text Available The ability to extract numerical information from different representation formats (e.g., equations, tables, or diagrams is a key component of mathematical competence but little is known about its neural correlate. Previous studies comparing mathematically less and more competent adults have focused on mental arithmetic and reported differences in left angular gyrus activity which were interpreted to reflect differential reliance on arithmetic fact retrieval during problem solving. The aim of the present functional magnetic resonance imaging (fMRI study was to investigate the brain correlates of mathematical competence in a task requiring the processing of typical mathematical representations. Twenty-eight adults of lower and higher mathematical competence worked on a representation matching task in which they had to evaluate whether the numerical information of a symbolic equation matches that of a bar chart. Two task conditions without and one condition with arithmetic demands were administered. Both competence groups performed equally well in the non-arithmetic conditions and only differed in accuracy in the condition requiring calculation. Activation contrasts between the groups revealed consistently stronger left angular gyrus activation in the more competent individuals across all three task conditions. The finding of competence-related activation differences independently of arithmetic demands suggests that more and less competent individuals differ in a cognitive process other than arithmetic fact retrieval. Specifically, it is argued that the stronger left angular gyrus activity in the more competent adults may reflect their higher proficiency in processing mathematical symbols. Moreover, the study demonstrates competence-related parietal activation differences that were not accompanied by differential experimental performance.

  5. Magnetic resonance brain tissue segmentation based on sparse representations

    Science.gov (United States)

    Rueda, Andrea

    2015-12-01

    Segmentation or delineation of specific organs and structures in medical images is an important task in the clinical diagnosis and treatment, since it allows to characterize pathologies through imaging measures (biomarkers). In brain imaging, segmentation of main tissues or specific structures is challenging, due to the anatomic variability and complexity, and the presence of image artifacts (noise, intensity inhomogeneities, partial volume effect). In this paper, an automatic segmentation strategy is proposed, based on sparse representations and coupled dictionaries. Image intensity patterns are singly related to tissue labels at the level of small patches, gathering this information in coupled intensity/segmentation dictionaries. This dictionaries are used within a sparse representation framework to find the projection of a new intensity image onto the intensity dictionary, and the same projection can be used with the segmentation dictionary to estimate the corresponding segmentation. Preliminary results obtained with two publicly available datasets suggest that the proposal is capable of estimating adequate segmentations for gray matter (GM) and white matter (WM) tissues, with an average overlapping of 0:79 for GM and 0:71 for WM (with respect to original segmentations).

  6. Event-related brain potentials reflect discourse-referential ambiguity in spoken language comprehension.

    NARCIS (Netherlands)

    J.J.A. van Berkum; C.M. Brown; P. Hagoort; P. Zwitserlood

    2003-01-01

    In two experiments, we explored the use of event-related brain potentials to selectively track the processes that establish reference during spoken language comprehension. Subjects listened to stories in which a particular noun phrase like "the girl" either uniquely referred to a single referent men

  7. Are ambiguity aversion and ambiguity intolerance identical? A neuroeconomics investigation.

    Science.gov (United States)

    Tanaka, Yusuke; Fujino, Junya; Ideno, Takashi; Okubo, Shigetaka; Takemura, Kazuhisa; Miyata, Jun; Kawada, Ryosaku; Fujimoto, Shinsuke; Kubota, Manabu; Sasamoto, Akihiko; Hirose, Kimito; Takeuchi, Hideaki; Fukuyama, Hidenao; Murai, Toshiya; Takahashi, Hidehiko

    2014-01-01

    In recent years, there has been growing interest in understanding a person's reaction to ambiguous situations, and two similar constructs related to ambiguity, "ambiguity aversion" and "ambiguity intolerance," are defined in different disciplines. In the field of economic decision-making research, "ambiguity aversion" represents a preference for known risks relative to unknown risks. On the other hand, in clinical psychology, "ambiguity intolerance" describes the tendency to perceive ambiguous situations as undesirable. However, it remains unclear whether these two notions derived from different disciplines are identical or not. To clarify this issue, we combined an economic task, psychological questionnaires, and voxel-based morphometry (VBM) of structural brain magnetic resonance imaging (MRI) in a sample of healthy volunteers. The individual ambiguity aversion tendency parameter, as measured by our economic task, was negatively correlated with agreeableness scores on the self-reported version of the Revised NEO Personality Inventory. However, it was not correlated with scores of discomfort with ambiguity, one of the subscales of the Need for Closure Scale. Furthermore, the ambiguity aversion tendency parameter was negatively correlated with gray matter (GM) volume of areas in the lateral prefrontal cortex and parietal cortex, whereas ambiguity intolerance was not correlated with GM volume in any region. Our results suggest that ambiguity aversion, described in decision theory, may not necessarily be identical to ambiguity intolerance, referred to in clinical psychology. Cautious applications of decision theory to clinical neuropsychiatry are recommended. PMID:25698984

  8. Are ambiguity aversion and ambiguity intolerance identical?: A neuroeconomics investigation.

    Directory of Open Access Journals (Sweden)

    Yusuke eTanaka

    2015-02-01

    Full Text Available In recent years, there has been growing interest in understanding a person’s reaction to ambiguous situations, and two similar constructs related to ambiguity, ambiguity aversion and ambiguity intolerance, are defined in different disciplines. In the field of economic decision-making research, ambiguity aversion represents a preference for known risks relative to unknown risks. On the other hand, in clinical psychology, ambiguity intolerance describes the tendency to perceive ambiguous situations as undesirable. However, it remains unclear whether these two notions derived from different disciplines are identical or not. To clarify this issue, we combined an economic task, psychological questionnaires, and voxel-based morphometry (VBM of structural brain magnetic resonance imaging (MRI in a sample of healthy volunteers. The individual ambiguity aversion tendency parameter, as measured by our economic task, was negatively correlated with agreeableness scores on the self-reported version of the Revised NEO Personality Inventory. However, it was not correlated with scores of discomfort with ambiguity, one of the subscales of the Need for Closure Scale. Furthermore, the ambiguity aversion tendency parameter was negatively correlated with gray matter (GM volume of areas in the lateral prefrontal cortex and parietal cortex, whereas ambiguity intolerance was not correlated with GM volume in any region. Our results suggest that ambiguity aversion, described in decision theory, may not necessarily be identical to ambiguity intolerance, referred in clinical psychology. Cautious applications of decision theory to clinical neuropsychiatry are recommended.

  9. Semantic Ambiguity and Perceived Ambiguity

    OpenAIRE

    Poesio, Massimo

    1995-01-01

    I explore some of the issues that arise when trying to establish a connection between the underspecification hypothesis pursued in the NLP literature and work on ambiguity in semantics and in the psychological literature. A theory of underspecification is developed `from the first principles', i.e., starting from a definition of what it means for a sentence to be semantically ambiguous and from what we know about the way humans deal with ambiguity. An underspecified language is specified as t...

  10. Ambiguous walls

    DEFF Research Database (Denmark)

    Mody, Astrid

    2012-01-01

    of “ambiguous walls” as a more “critical” approach to design [1]. The concept of ambiguous walls refers to the diffuse status a lumious and possibly responsive wall will have. Instead of confining it can open up. Instead of having a static appearance, it becomes a context over time. Instead of being hard...

  11. Brain-to-text: Decoding spoken phrases from phone representations in the brain

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    Christian eHerff

    2015-06-01

    Full Text Available It has long been speculated whether communication between humans and machines based on natural speech related cortical activity is possible. Over the past decade, studies have suggested that it is feasible to recognize isolated aspects of speech from neural signals, such as auditory features, phones or one of a few isolated words. However, until now it remained an unsolved challenge to decode continuously spoken speech from the neural substrate associated with speech and language processing. Here, we show for the first time that continuously spoken speech can be decoded into the expressed words from intracranial electrocorticographic (ECoG recordings. Specifically, we implemented a system, which we call Brain-To-Text that models single phones, employs techniques from automatic speech recognition (ASR, and thereby transforms brain activity while speaking into the corresponding textual representation. Our results demonstrate that our system achieved word error rates as low as 25% and phone error rates below 50%. Additionally, our approach contributes to the current understanding of the neural basis of continuous speech production by identifying those cortical regions that hold substantial information about individual phones. In conclusion, the Brain-To-Text system described in this paper represents an important step towards human-machine communication based on imagined speech.

  12. OPTIMAL REPRESENTATION OF MER SIGNALS APPLIED TO THE IDENTIFICATION OF BRAIN STRUCTURES DURING DEEP BRAIN STIMULATION

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    Hernán Darío Vargas Cardona

    2015-07-01

    Full Text Available Identification of brain signals from microelectrode recordings (MER is a key procedure during deep brain stimulation (DBS applied in Parkinson’s disease patients. The main purpose of this research work is to identify with high accuracy a brain structure called subthalamic nucleus (STN, since it is the target structure where the DBS achieves the best therapeutic results. To do this, we present an approach for optimal representation of MER signals through method of frames. We obtain coefficients that minimize the Euclidean norm of order two. From optimal coefficients, we extract some features from signals combining the wavelet packet and cosine dictionaries. For a comparison frame with the state of the art, we also process the signals using the discrete wavelet transform (DWT with several mother functions. We validate the proposed methodology in a real data base. We employ simple supervised machine learning algorithms, as the K-Nearest Neighbors classifier (K-NN, a linear Bayesian classifier (LDC and a quadratic Bayesian classifier (QDC. Classification results obtained with the proposed method improves significantly the performance of the DWT. We achieve a positive identification of the STN superior to 97,6%. Identification outcomes achieved by the MOF are highly accurate, as we can potentially get a false positive rate of less than 2% during the DBS.

  13. Brain-to-text: decoding spoken phrases from phone representations in the brain.

    Science.gov (United States)

    Herff, Christian; Heger, Dominic; de Pesters, Adriana; Telaar, Dominic; Brunner, Peter; Schalk, Gerwin; Schultz, Tanja

    2015-01-01

    It has long been speculated whether communication between humans and machines based on natural speech related cortical activity is possible. Over the past decade, studies have suggested that it is feasible to recognize isolated aspects of speech from neural signals, such as auditory features, phones or one of a few isolated words. However, until now it remained an unsolved challenge to decode continuously spoken speech from the neural substrate associated with speech and language processing. Here, we show for the first time that continuously spoken speech can be decoded into the expressed words from intracranial electrocorticographic (ECoG) recordings.Specifically, we implemented a system, which we call Brain-To-Text that models single phones, employs techniques from automatic speech recognition (ASR), and thereby transforms brain activity while speaking into the corresponding textual representation. Our results demonstrate that our system can achieve word error rates as low as 25% and phone error rates below 50%. Additionally, our approach contributes to the current understanding of the neural basis of continuous speech production by identifying those cortical regions that hold substantial information about individual phones. In conclusion, the Brain-To-Text system described in this paper represents an important step toward human-machine communication based on imagined speech. PMID:26124702

  14. Situs ambiguous

    International Nuclear Information System (INIS)

    The case of a female child is described who presented with recurrent respiratory infections and 'recurrint right subphrenic abscess.' Detailed radiological work-up identified situs ambiguous abdominis with bronchiectasis, duodenal malrotation, umbilical hernia and spina bifida. (author)

  15. Brain activity associated with translation from a visual to a symbolic representation in algebra and geometry.

    Science.gov (United States)

    Leikin, Mark; Waisman, Ilana; Shaul, Shelley; Leikin, Roza

    2014-03-01

    This paper presents a small part of a larger interdisciplinary study that investigates brain activity (using event related potential methodology) of male adolescents when solving mathematical problems of different types. The study design links mathematics education research with neurocognitive studies. In this paper we performed a comparative analysis of brain activity associated with the translation from visual to symbolic representations of mathematical objects in algebra and geometry. Algebraic tasks require translation from graphical to symbolic representation of a function, whereas tasks in geometry require translation from a drawing of a geometric figure to a symbolic representation of its property. The findings demonstrate that electrical activity associated with the performance of geometrical tasks is stronger than that associated with solving algebraic tasks. Additionally, we found different scalp topography of the brain activity associated with algebraic and geometric tasks. Based on these results, we argue that problem solving in algebra and geometry is associated with different patterns of brain activity.

  16. A Tableaux Calculus for Ambiguous Quantification

    OpenAIRE

    Monz, Christof; de Rijke, Maarten

    2000-01-01

    Coping with ambiguity has recently received a lot of attention in natural language processing. Most work focuses on the semantic representation of ambiguous expressions. In this paper we complement this work in two ways. First, we provide an entailment relation for a language with ambiguous expressions. Second, we give a sound and complete tableaux calculus for reasoning with statements involving ambiguous quantification. The calculus interleaves partial disambiguation steps with steps in a t...

  17. Representations of Value in the Brain: An Embarrassment of Riches?

    Science.gov (United States)

    Stott, Jeffrey J; Redish, A David

    2015-06-01

    Over the past two decades, neuroscientists have increasingly turned their attention to the question of how the brain implements decisions between differently valued options. This emerging field, called neuroeconomics, has made quick progress in identifying a plethora of brain areas that track or are modulated by reward value. However, it is still unclear how and where in the brain value coding takes place. A primate study by Strait and colleagues in this issue of PLOS Biology finds overlapping signals of value coding in two brain regions central to the valuation process: the ventromedial prefrontal cortex and the ventral striatum. This finding reconciles the primate and rodent literatures, provides valuable insight into the complexity of value computation, and helps set the agenda for future work in this area. PMID:26086790

  18. Representations of Value in the Brain: An Embarrassment of Riches?

    Directory of Open Access Journals (Sweden)

    Jeffrey J Stott

    2015-06-01

    Full Text Available Over the past two decades, neuroscientists have increasingly turned their attention to the question of how the brain implements decisions between differently valued options. This emerging field, called neuroeconomics, has made quick progress in identifying a plethora of brain areas that track or are modulated by reward value. However, it is still unclear how and where in the brain value coding takes place. A primate study by Strait and colleagues in this issue of PLOS Biology finds overlapping signals of value coding in two brain regions central to the valuation process: the ventromedial prefrontal cortex and the ventral striatum. This finding reconciles the primate and rodent literatures, provides valuable insight into the complexity of value computation, and helps set the agenda for future work in this area.

  19. Invariance between subjects of brain wave representations of language

    OpenAIRE

    Suppes, Patrick; Han, Bing; Epelboim, Julie; Lu, Zhong-Lin

    1999-01-01

    In three experiments, electric brain waves of 19 subjects were recorded under several different experimental conditions for two purposes. One was to test how well we could recognize which sentence, from a set of 24 or 48 sentences, was being processed in the cortex. The other was to study the invariance of brain waves between subjects. As in our earlier work, the analysis consisted of averaging over trials to create prototypes and test samples, to both of which Fourier transforms were applied...

  20. Oscillatory Activity in the Infant Brain and the Representation of Small Numbers

    Science.gov (United States)

    Leung, Sumie; Mareschal, Denis; Rowsell, Renee; Simpson, David; Iaria, Leon; Grbic, Amanda; Kaufman, Jordy

    2016-01-01

    Gamma-band oscillatory activity (GBA) is an established neural signature of sustained occluded object representation in infants and adults. However, it is not yet known whether the magnitude of GBA in the infant brain reflects the quantity of occluded items held in memory. To examine this, we compared GBA of 6–8 month-old infants during occlusion periods after the representation of two objects vs. that of one object. We found that maintaining a representation of two objects during occlusion resulted in significantly greater GBA relative to maintaining a single object. Further, this enhancement was located in the right occipital region, which is consistent with previous object representation research in adults and infants. We conclude that enhanced GBA reflects neural processes underlying infants’ representation of small numbers. PMID:26903821

  1. Lived Experiences of Iranian Nurses Caring for Brain Death Organ Donor Patients: Caring as “Halo of Ambiguity and Doubt”

    Science.gov (United States)

    Keshtkaran, Zahra; Sharif, Farkhondeh; Navab, Elham; Gholamzadeh, Sakineh

    2016-01-01

    Background: Brain death is a concept in which its criteria have been expressed as documentations in Harvard Committee of Brain Death. The various perceptions of caregiver nurses for brain death patients may have effect on the chance of converting potential donors into actual organ donors. Objective: The present study has been conducted in order to perceive the experiences of nurses in care-giving to the brain death of organ donor patients. Methods: This qualitative study was carried out by means of Heidegger’s hermeneutic phenomenology. Eight nurses who have been working in ICU were interviewed. The semi-structured interviews were recorded by a tape-recorder and the given texts were transcribed and the analyses were done by Van-Mannen methodology and (thematic) analysis. Results: One of the foremost themes extracted from this study included ‘Halo of ambiguity and doubt’ that comprised of two sub-themes of ‘having unreasonable hope’ and ‘Conservative acceptance of brain death’. The unreasonable hope included lack of trust (uncertainty) in diagnosis and verification of brain death, passing through denial wall, and avoidance from explicit and direct disclosure of brain death in patients’ family. In this investigation, the nurses were involved in a type of ambiguity and doubt in care-giving to the potentially brain death of organ donor patients, which were also evident in their interaction with patients’ family and for this reason, they did not definitely announce the brain death and so far they hoped for treatment of the given patient. Such confusion and hesitance both caused annoyance of nurses and strengthening the denial of patients’ family to be exposed to death. Conclusion: The results of this study reveal the fundamental perceived care-giving of brain death in organ donor patients and led to developing some strategies to improve care-giving and achievement in donation of the given organ and necessity for presentation of educational and

  2. Invariance of brain-wave representations of simple visual images and their names

    OpenAIRE

    Suppes, Patrick; Han, Bing; Epelboim, Julie; Lu, Zhong-Lin

    1999-01-01

    In two experiments, electric brain waves of 14 subjects were recorded under several different conditions to study the invariance of brain-wave representations of simple patches of colors and simple visual shapes and their names, the words blue, circle, etc. As in our earlier work, the analysis consisted of averaging over trials to create prototypes and test samples, to both of which Fourier transforms were applied, followed by filtering and an inverse transformation to the time domain. A leas...

  3. Media representations of early human development: protecting, feeding and loving the developing brain.

    Science.gov (United States)

    O'Connor, Cliodhna; Joffe, Helene

    2013-11-01

    The public profile of neurodevelopmental research has expanded in recent years. This paper applies social representations theory to explore how early brain development was represented in the UK print media in the first decade of the 21st century. A thematic analysis was performed on 505 newspaper articles published between 2000 and 2010 that discussed early brain development. Media coverage centred around concern with 'protecting' the prenatal brain (identifying threats to foetal neurodevelopment), 'feeding' the infant brain (indicating the patterns of nutrition that enhance brain development) and 'loving' the young child's brain (elucidating the developmental significance of emotionally nurturing family environments). The media focused almost exclusively on the role of parental action in promoting optimal neurodevelopment, rarely acknowledging wider structural, cultural or political means of supporting child development. The significance of parental care was intensified by deterministic interpretations of critical periods, which implied that inappropriate parental input would produce profound and enduring neurobiological impairments. Neurodevelopmental research was also used to promulgate normative judgements concerning the acceptability of certain gender roles and family contexts. The paper argues that media representations of neurodevelopment stress parental responsibility for shaping a child's future while relegating the contributions of genetic or wider societal factors, and examines the consequences of these representations for society and family life. PMID:23273760

  4. The representation of material categories in the brain

    Directory of Open Access Journals (Sweden)

    Richard Henrikus Augustinus Hubertus Jacobs

    2014-03-01

    Full Text Available Using textures mapped onto virtual nonsense objects, it has recently been shown that early visual cortex plays an important role in processing material properties. Here, we examined brain activation to photographs of materials, consisting of wood, stone, metal and fabric surfaces. These photographs were close-ups in the sense that the materials filled the image. In the first experiment, observers categorized the material in each image (i.e., wood, stone, metal, or fabric, while in an fMRI-scanner. We predicted the assigned material category using the obtained voxel patterns using a linear classifier. Region-of-interest and whole-brain analyses demonstrated material coding in the early visual regions, with lower accuracies for more anterior regions. There was little evidence for material coding in other brain regions. In the second experiment, we used an adaptation paradigm to reveal additional brain areas involved in the perception of material categories. Participants viewed images of wood, stone, metal, and fabric, presented in blocks with images of either different material categories (no adaptation or images of different samples from the same material category (material adaptation. To measure baseline activation, blocks with the same material sample were presented (baseline adaptation. Material adaptation effects were found mainly in the parahippocampal gyrus, in agreement with fMRI-studies of texture perception. Our findings suggest that the parahippocampal gyrus, early visual cortex, and possibly the supramarginal gyrus are involved in the perception of material categories, but in different ways. The different outcomes from the two studies are likely due to inherent differences between the two paradigms. A third experiment suggested, based on anatomical overlap between activations, that spatial frequency information is important for within-category material discrimination.

  5. Lexical ambiguity in sentence comprehension

    OpenAIRE

    Mason, Robert A.; Just, Marcel Adam

    2007-01-01

    An event-related fMRI paradigm was used to investigate brain activity during the reading of sentences containing either a lexically ambiguous word or an unambiguous control word. Higher levels of activation occurred during the reading of sentences containing a lexical ambiguity. Furthermore, the activated cortical network differed, depending on: (1) whether the sentence contained a balanced (i.e., both meanings equally likely) or a biased (i.e., one meaning more likely than other meanings) am...

  6. Robust brain parcellation using sparse representation on resting-state fMRI.

    Science.gov (United States)

    Zhang, Yu; Caspers, Svenja; Fan, Lingzhong; Fan, Yong; Song, Ming; Liu, Cirong; Mo, Yin; Roski, Christian; Eickhoff, Simon; Amunts, Katrin; Jiang, Tianzi

    2015-11-01

    Resting-state fMRI (rs-fMRI) has been widely used to segregate the brain into individual modules based on the presence of distinct connectivity patterns. Many parcellation methods have been proposed for brain parcellation using rs-fMRI, but their results have been somewhat inconsistent, potentially due to various types of noise. In this study, we provide a robust parcellation method for rs-fMRI-based brain parcellation, which constructs a sparse similarity graph based on the sparse representation coefficients of each seed voxel and then uses spectral clustering to identify distinct modules. Both the local time-varying BOLD signals and whole-brain connectivity patterns may be used as features and yield similar parcellation results. The robustness of our method was tested on both simulated and real rs-fMRI datasets. In particular, on simulated rs-fMRI data, sparse representation achieved good performance across different noise levels, including high accuracy of parcellation and high robustness to noise. On real rs-fMRI data, stable parcellation of the medial frontal cortex (MFC) and parietal operculum (OP) were achieved on three different datasets, with high reproducibility within each dataset and high consistency across these results. Besides, the parcellation of MFC was little influenced by the degrees of spatial smoothing. Furthermore, the consistent parcellation of OP was also well corresponding to cytoarchitectonic subdivisions and known somatotopic organizations. Our results demonstrate a new promising approach to robust brain parcellation using resting-state fMRI by sparse representation.

  7. Modality-independent representations of small quantities based on brain activation patterns.

    Science.gov (United States)

    Damarla, Saudamini Roy; Cherkassky, Vladimir L; Just, Marcel Adam

    2016-04-01

    Machine learning or MVPA (Multi Voxel Pattern Analysis) studies have shown that the neural representation of quantities of objects can be decoded from fMRI patterns, in cases where the quantities were visually displayed. Here we apply these techniques to investigate whether neural representations of quantities depicted in one modality (say, visual) can be decoded from brain activation patterns evoked by quantities depicted in the other modality (say, auditory). The main finding demonstrated, for the first time, that quantities of dots were decodable by a classifier that was trained on the neural patterns evoked by quantities of auditory tones, and vice-versa. The representations that were common across modalities were mainly right-lateralized in frontal and parietal regions. A second finding was that the neural patterns in parietal cortex that represent quantities were common across participants. These findings demonstrate a common neuronal foundation for the representation of quantities across sensory modalities and participants and provide insight into the role of parietal cortex in the representation of quantity information.

  8. Dynamics of trimming the content of face representations for categorization in the brain.

    Directory of Open Access Journals (Sweden)

    Nicola J van Rijsbergen

    2009-11-01

    Full Text Available To understand visual cognition, it is imperative to determine when, how and with what information the human brain categorizes the visual input. Visual categorization consistently involves at least an early and a late stage: the occipito-temporal N170 event related potential related to stimulus encoding and the parietal P300 involved in perceptual decisions. Here we sought to understand how the brain globally transforms its representations of face categories from their early encoding to the later decision stage over the 400 ms time window encompassing the N170 and P300 brain events. We applied classification image techniques to the behavioral and electroencephalographic data of three observers who categorized seven facial expressions of emotion and report two main findings: (1 over the 400 ms time course, processing of facial features initially spreads bilaterally across the left and right occipito-temporal regions to dynamically converge onto the centro-parietal region; (2 concurrently, information processing gradually shifts from encoding common face features across all spatial scales (e.g., the eyes to representing only the finer scales of the diagnostic features that are richer in useful information for behavior (e.g., the wide opened eyes in 'fear'; the detailed mouth in 'happy'. Our findings suggest that the brain refines its diagnostic representations of visual categories over the first 400 ms of processing by trimming a thorough encoding of features over the N170, to leave only the detailed information important for perceptual decisions over the P300.

  9. Stimulating the brain's language network: Syntactic ambiguity resolution after TMS to the Inferior Frontal Gyrus and Middle Temporal Gyrus

    NARCIS (Netherlands)

    Acheson, D.J.; Hagoort, P.

    2013-01-01

    The posterior middle temporal gyrus (MTG) and inferior frontal gyrus (IFG) are two critical nodes of the brain's language network. Previous neuroimaging evidence has supported a dissociation in language comprehension in which parts of the MTG are involved in the retrieval of lexical syntactic inform

  10. Invariance of brain-wave representations of simple visual images and their names.

    Science.gov (United States)

    Suppes, P; Han, B; Epelboim, J; Lu, Z L

    1999-12-01

    In two experiments, electric brain waves of 14 subjects were recorded under several different conditions to study the invariance of brain-wave representations of simple patches of colors and simple visual shapes and their names, the words blue, circle, etc. As in our earlier work, the analysis consisted of averaging over trials to create prototypes and test samples, to both of which Fourier transforms were applied, followed by filtering and an inverse transformation to the time domain. A least-squares criterion of fit between prototypes and test samples was used for classification. The most significant results were these. By averaging over different subjects, as well as trials, we created prototypes from brain waves evoked by simple visual images and test samples from brain waves evoked by auditory or visual words naming the visual images. We correctly recognized from 60% to 75% of the test-sample brain waves. The general conclusion is that simple shapes such as circles and single-color displays generate brain waves surprisingly similar to those generated by their verbal names. These results, taken together with extensive psychological studies of auditory and visual memory, strongly support the solution proposed for visual shapes, by Bishop Berkeley and David Hume in the 18th century, to the long-standing problem of how the mind represents simple abstract ideas.

  11. Ambiguity in sentence processing.

    Science.gov (United States)

    Altmann, G T

    1998-04-01

    As listeners and readers, we rarely notice the ambiguities that pervade our everyday language. When we hear the proverb `Time flies like an arrow' we might ponder its meaning, but not the fact that there are almost 100 grammatically permissible interpretations of this short sentence. On occasion, however, we do notice sentential ambiguity: headlines, such as `Two Sisters Reunited After 18 Years in Checkout Counter', are amusing because they so consistently lead to the unintended interpretation (presumably, the sisters did not spend 18 years at the checkout). It is this consistent preference for one interpretation-and one grammatical structure-rather than another that has fuelled research into sentence processing for more than 20 years. Until relatively recently, the dominant belief had been that these preferences arise from general principles that underlie our use of grammar, with certain grammatical constructions being preferred over others. There has now accrued, however, a considerable body of evidence demonstrating that these preferences are not absolute, but can change in particular circumstances. With this evidence have come new theories of sentence processing, some of which, at first glance, radically question the standard notions of linguistic representation, grammar and understanding.

  12. Rules rule! Brain activity dissociates the representations of stimulus contingencies with varying levels of complexity.

    Science.gov (United States)

    Tse, Chun-Yu; Low, Kathy A; Fabiani, Monica; Gratton, Gabriele

    2012-09-01

    The significance of stimuli is linked not only to their nature but also to the sequential structure in which they are embedded, which gives rise to contingency rules. Humans have an extraordinary ability to extract and exploit these rules, as exemplified by the role of grammar and syntax in language. To study the brain representations of contingency rules, we recorded ERPs and event-related optical signal (EROS; which uses near-infrared light to measure the optical changes associated with neuronal responses). We used sequences of high- and low-frequency tones varying according to three contingency rules, which were orthogonally manipulated and differed in processing requirements: A Single Repetition rule required only template matching, a Local Probability rule required relating a stimulus to its context, and a Global Probability rule could be derived through template matching or with reference to the global sequence context. ERP activity at 200-300 msec was related to the Single Repetition and Global Probability rules (reflecting access to representations based on template matching), whereas longer-latency activity (300-450 msec) was related to the Local Probability and Global Probability rules (reflecting access to representations incorporating contextual information). EROS responses with corresponding latencies indicated that the earlier activity involved the superior temporal gyrus, whereas later responses involved a fronto-parietal network. This suggests that the brain can simultaneously hold different models of stimulus contingencies at different levels of the information processing system according to their processing requirements, as indicated by the latency and location of the corresponding brain activity.

  13. Maplike Representation of Celestial E-Vector Orientations in the Brain of an Insect

    Science.gov (United States)

    Heinze, Stanley; Homberg, Uwe

    2007-02-01

    For many insects, the polarization pattern of the blue sky serves as a compass cue for spatial navigation. E-vector orientations are detected by photoreceptors in a dorsal rim area of the eye. Polarized-light signals from both eyes are finally integrated in the central complex, a brain area consisting of two subunits, the protocerebral bridge and the central body. Here we show that a topographic representation of zenithal E-vector orientations underlies the columnar organization of the protocerebral bridge in a locust. The maplike arrangement is highly suited to signal head orientation under the open sky.

  14. How Ambiguous is the Structural Ambiguity.

    OpenAIRE

    Masda Surti Simatupang

    2007-01-01

    A word, phrase, or sentence is ambiguous if it has more than one meaning. The ambiguity, however, can be noticed if one really has a linguistic knowledge on how to analyze the phrase or sentence. Of the two kinds of ambiguity, lexical and structural, the latter is the one which is explored further in this paper. Structural ambiguity occurs when a phrase or sentence has more than one underlying structure. The phrase can be disambiguated by putting it in a sentence with some sort of...

  15. Noise in attractor networks in the brain produced by graded firing rate representations.

    Directory of Open Access Journals (Sweden)

    Tristan J Webb

    Full Text Available Representations in the cortex are often distributed with graded firing rates in the neuronal populations. The firing rate probability distribution of each neuron to a set of stimuli is often exponential or gamma. In processes in the brain, such as decision-making, that are influenced by the noise produced by the close to random spike timings of each neuron for a given mean rate, the noise with this graded type of representation may be larger than with the binary firing rate distribution that is usually investigated. In integrate-and-fire simulations of an attractor decision-making network, we show that the noise is indeed greater for a given sparseness of the representation for graded, exponential, than for binary firing rate distributions. The greater noise was measured by faster escaping times from the spontaneous firing rate state when the decision cues are applied, and this corresponds to faster decision or reaction times. The greater noise was also evident as less stability of the spontaneous firing state before the decision cues are applied. The implication is that spiking-related noise will continue to be a factor that influences processes such as decision-making, signal detection, short-term memory, and memory recall even with the quite large networks found in the cerebral cortex. In these networks there are several thousand recurrent collateral synapses onto each neuron. The greater noise with graded firing rate distributions has the advantage that it can increase the speed of operation of cortical circuitry.

  16. Image ambiguity and fluency.

    Directory of Open Access Journals (Sweden)

    Martina Jakesch

    Full Text Available Ambiguity is often associated with negative affective responses, and enjoying ambiguity seems restricted to only a few situations, such as experiencing art. Nevertheless, theories of judgment formation, especially the "processing fluency account", suggest that easy-to-process (non-ambiguous stimuli are processed faster and are therefore preferred to (ambiguous stimuli, which are hard to process. In a series of six experiments, we investigated these contrasting approaches by manipulating fluency (presentation duration: 10 ms, 50 ms, 100 ms, 500 ms, 1000 ms and testing effects of ambiguity (ambiguous versus non-ambiguous pictures of paintings on classification performance (Part A; speed and accuracy and aesthetic appreciation (Part B; liking and interest. As indicated by signal detection analyses, classification accuracy increased with presentation duration (Exp. 1a, but we found no effects of ambiguity on classification speed (Exp. 1b. Fifty percent of the participants were able to successfully classify ambiguous content at a presentation duration of 100 ms, and at 500 ms even 75% performed above chance level. Ambiguous artworks were found more interesting (in conditions 50 ms to 1000 ms and were preferred over non-ambiguous stimuli at 500 ms and 1000 ms (Exp. 2a - 2c, 3. Importantly, ambiguous images were nonetheless rated significantly harder to process as non-ambiguous images. These results suggest that ambiguity is an essential ingredient in art appreciation even though or maybe because it is harder to process.

  17. Retrieval of Brain Tumors by Adaptive Spatial Pooling and Fisher Vector Representation.

    Science.gov (United States)

    Cheng, Jun; Yang, Wei; Huang, Meiyan; Huang, Wei; Jiang, Jun; Zhou, Yujia; Yang, Ru; Zhao, Jie; Feng, Yanqiu; Feng, Qianjin; Chen, Wufan

    2016-01-01

    Content-based image retrieval (CBIR) techniques have currently gained increasing popularity in the medical field because they can use numerous and valuable archived images to support clinical decisions. In this paper, we concentrate on developing a CBIR system for retrieving brain tumors in T1-weighted contrast-enhanced MRI images. Specifically, when the user roughly outlines the tumor region of a query image, brain tumor images in the database of the same pathological type are expected to be returned. We propose a novel feature extraction framework to improve the retrieval performance. The proposed framework consists of three steps. First, we augment the tumor region and use the augmented tumor region as the region of interest to incorporate informative contextual information. Second, the augmented tumor region is split into subregions by an adaptive spatial division method based on intensity orders; within each subregion, we extract raw image patches as local features. Third, we apply the Fisher kernel framework to aggregate the local features of each subregion into a respective single vector representation and concatenate these per-subregion vector representations to obtain an image-level signature. After feature extraction, a closed-form metric learning algorithm is applied to measure the similarity between the query image and database images. Extensive experiments are conducted on a large dataset of 3604 images with three types of brain tumors, namely, meningiomas, gliomas, and pituitary tumors. The mean average precision can reach 94.68%. Experimental results demonstrate the power of the proposed algorithm against some related state-of-the-art methods on the same dataset. PMID:27273091

  18. On Ambiguity and Organizations

    Science.gov (United States)

    Lerner, Allan W.

    1978-01-01

    Ambiguity in the structure of decision-makers relationships is considered for the strategic opportunities it offers calculating actors. Ambiguity is discussed in the context of reciprocity, authority, and jurisdictional facets of relationships. The value of ambiguity as a common theme linking rational actor and system level concepts is also…

  19. Scope ambiguities and conditionals

    NARCIS (Netherlands)

    Over, David; Douven, Igor; Verbrugge, Sara

    2013-01-01

    Scope ambiguities in natural language have been much discussed by linguists and philosophers. There has been some psychological work on the scope ambiguities of negation, but we present the first experiments on modal scope ambiguities in conditionals, with special attention paid to the scope ambigui

  20. English and Chinese language ambiguity

    Institute of Scientific and Technical Information of China (English)

    程海

    2009-01-01

    This article from the Voice of Ambiguity,Lexical Ambiguity and Ambiguity in the three aspects of the grammatical structure of English and Chinese languages are compared ambiguity And analysis.Ambiguity in English and Chinese language through the comparison,resulted in two languages to explore the reasons for ambiguity;analysis of the characteristics of English language ambiguities;Research Should not be some ambiguity on how to avoid the emergence of the phenomenon.

  1. Cognitive Interpretations of Ambiguous Visual Stimuli

    OpenAIRE

    Naber, Marnix

    2012-01-01

    Brains can sense and distinguish signals from background noise in physical environments, and recognize and classify them as distinct entities. Ambiguity is an inherent part of this process. It is a cognitive property that is generated by the noisy character of the signals, and by the design of the sensory systems that process them. Stimuli can be ambiguous if they are noisy, incomplete, or only briefly sensed. Such conditions may ...

  2. Ambiguity in Securitization Markets

    OpenAIRE

    Anderson, Alyssa G.

    2015-01-01

    During the financial crisis of 2008, origination and trading in asset-backed securities markets dropped dramatically. I present a model with ambiguity averse investors to explain how such a market freeze could occur and to investigate how ambiguity affects origination and securitization decisions. The model captures many features of the crisis, including market freezes and fire sales, as well as the timing and duration of the freeze. The presence of ambiguity also reduces real economic activi...

  3. Modelling the Effects of Semantic Ambiguity in Word Recognition

    Science.gov (United States)

    Rodd, Jennifer M.; Gaskell, M. Gareth; Marslen-Wilson, William D.

    2004-01-01

    Most words in English are ambiguous between different interpretations; words can mean different things in different contexts. We investigate the implications of different types of semantic ambiguity for connectionist models of word recognition. We present a model in which there is competition to activate distributed semantic representations. The…

  4. An approach to the symbolic representation of brain arteriovenous malformations for management and treatment planning

    Energy Technology Data Exchange (ETDEWEB)

    Orlowski, Piotr; Noble, Alison [University of Oxford, Institute of Biomedical Engineering, Department of Engineering Science, Oxford (United Kingdom); Mahmud, Imran; Kamran, Mudassar; Byrne, James V. [University of Oxford, John Radcliffe Hospital, Nuffield Department of Surgical Sciences, Oxford (United Kingdom); Summers, Paul [University of Oxford, John Radcliffe Hospital, Nuffield Department of Surgical Sciences, Oxford (United Kingdom); University of Modena and Reggio Emilia, Department of Biomedical, Metabolic and Neural Sciences, Modena (Italy); Ventikos, Yiannis [University College London, Department of Mechanical Engineering, London (United Kingdom)

    2014-03-15

    There is currently no standardised approach to arteriovenous malformation (AVM) reporting. Existing AVM classification systems focuses on angioarchitectural features and omit haemodynamic, anatomical and topological parameters intuitively used by therapists. We introduce a symbolic vocabulary to represent the state of an AVM of the brain at different stages of treatment. The vocabulary encompasses the main anatomic and haemodynamic features of interest in treatment planning and provides shorthand symbols to represent the interventions themselves in a schematic representation. The method was presented to 50 neuroradiologists from14 countries during a workshop and graded 7.34 ± 1.92 out of ten for its usefulness as means of standardising and facilitating communication between clinicians and allowing comparisons between AVM cases. Feedback from the survey was used to revise the method and improve its completeness. For an AVM test case, participants were asked to produce a conventional written report and subsequently a diagrammatic report. The two required, on average, 6.19 ± 2.05 and 5.09 ± 3.01 min, respectively. Eighteen participants said that producing the diagram changed the way they thought about the AVM test case. Introduced into routine practice, the diagrams would represent a step towards a standardised approach to AVM reporting with consequent benefits for comparative analysis and communication as well as for identifying best treatment strategies. (orig.)

  5. An approach to the symbolic representation of brain arteriovenous malformations for management and treatment planning

    International Nuclear Information System (INIS)

    There is currently no standardised approach to arteriovenous malformation (AVM) reporting. Existing AVM classification systems focuses on angioarchitectural features and omit haemodynamic, anatomical and topological parameters intuitively used by therapists. We introduce a symbolic vocabulary to represent the state of an AVM of the brain at different stages of treatment. The vocabulary encompasses the main anatomic and haemodynamic features of interest in treatment planning and provides shorthand symbols to represent the interventions themselves in a schematic representation. The method was presented to 50 neuroradiologists from14 countries during a workshop and graded 7.34 ± 1.92 out of ten for its usefulness as means of standardising and facilitating communication between clinicians and allowing comparisons between AVM cases. Feedback from the survey was used to revise the method and improve its completeness. For an AVM test case, participants were asked to produce a conventional written report and subsequently a diagrammatic report. The two required, on average, 6.19 ± 2.05 and 5.09 ± 3.01 min, respectively. Eighteen participants said that producing the diagram changed the way they thought about the AVM test case. Introduced into routine practice, the diagrams would represent a step towards a standardised approach to AVM reporting with consequent benefits for comparative analysis and communication as well as for identifying best treatment strategies. (orig.)

  6. Processing Coordination Ambiguity

    Science.gov (United States)

    Engelhardt, Paul E.; Ferreira, Fernanda

    2010-01-01

    We examined temporarily ambiguous coordination structures such as "put the butter in the bowl and the pan on the towel." Minimal Attachment predicts that the ambiguous noun phrase "the pan" will be interpreted as a noun-phrase coordination structure because it is syntactically simpler than clausal coordination. Constraint-based theories assume…

  7. Exploring ambiguous realms

    DEFF Research Database (Denmark)

    Clemensen, Nana

    2016-01-01

    In Hang'ombe Village in rural Zambia, the relative lack of physical boundaries between the activities of family members allow children to observe the actions and discussions of adults on close hand, exposing them to the ambiguities of daily life. Children explore these ambiguities...

  8. Representation of the verb's argument-structure in the human brain

    Directory of Open Access Journals (Sweden)

    Assadollahi Ramin

    2008-07-01

    Full Text Available Abstract Background A verb's argument structure defines the number and relationships of participants needed for a complete event. One-argument (intransitive verbs require only a subject to make a complete sentence, while two- and three-argument verbs (transitives and ditransitives normally take direct and indirect objects. Cortical responses to verbs embedded into sentences (correct or with syntactic violations indicate the processing of the verb's argument structure in the human brain. The two experiments of the present study examined whether and how this processing is reflected in distinct spatio-temporal cortical response patterns to isolated verbs and/or verbs presented in minimal context. Results The magnetoencephalogram was recorded while 22 native German-speaking adults saw 130 German verbs, presented one at a time for 150 ms each in experiment 1. Verb-evoked electromagnetic responses at 250 – 300 ms after stimulus onset, analyzed in source space, were higher in the left middle temporal gyrus for verbs that take only one argument, relative to two- and three-argument verbs. In experiment 2, the same verbs (presented in different order were preceded by a proper name specifying the subject of the verb. This produced additional activation between 350 and 450 ms in or near the left inferior frontal gyrus, activity being larger and peaking earlier for one-argument verbs that required no further arguments to form a complete sentence. Conclusion Localization of sources of activity suggests that the activation in temporal and frontal regions varies with the degree by which representations of an event as a part of the verbs' semantics are completed during parsing.

  9. Audio representations of multi-channel EEG: a new tool for diagnosis of brain disorders

    OpenAIRE

    Vialatte, François B.; Dauwels, Justin; Musha, Toshimitsu; Cichocki, Andrzej

    2012-01-01

    Objective: The objective of this paper is to develop audio representations of electroencephalographic (EEG) multichannel signals, useful for medical practitioners and neuroscientists. The fundamental question explored in this paper is whether clinically valuable information contained in the EEG, not available from the conventional graphical EEG representation, might become apparent through audio representations. Methods and Materials: Music scores are generated from sparse time-frequency maps...

  10. The Ambiguity of Macbeth

    Institute of Scientific and Technical Information of China (English)

    徐松健

    2014-01-01

    The hero Macbeth in Shakespeare’s play Macbeth is a man of ambiguity. He feels like getting the throne, but dares not take responsibility to be a king. He seems courageous, but deep in his character he is inferior.

  11. Exploring ambiguous realms

    DEFF Research Database (Denmark)

    Clemensen, Nana

    2016-01-01

    In Hang'ombe Village in rural Zambia, the relative lack of physical boundaries between the activities of family members allow children to observe the actions and discussions of adults on close hand, exposing them to the ambiguities of daily life. Children explore these ambiguities in their intera...... interactions, testing social roles and conventions. This article explores the vigilance and creative agency displayed by Hang'ombe children, in an environment spurring their acquisition of distinct social and discursive skills....

  12. Neural responses to category ambiguous words.

    Science.gov (United States)

    Conwell, Erin

    2015-03-01

    Category ambiguous words (like hug and swing) have the potential to complicate both learning and processing of language. However, uses of such words may be disambiguated by acoustic differences that depend on the category of use. This article uses an event-related potential (ERP) technique to ask whether adult native speakers of English show neural sensitivity to those differences. The results indicate that noun and verb tokens of ambiguous words produce differences in the amplitude of the ERP response over left anterior sites as early as 100ms following stimulus onset and persisting for over 400ms. Nonsense words extracted from noun and verb contexts do not show such differences. These findings suggest that the acoustic differences between noun and verb tokens of ambiguous words are perceived and processed by adults and may be part of the lexical representation of the word. PMID:25637057

  13. Regularization ambiguities in loop quantum gravity

    International Nuclear Information System (INIS)

    One of the main achievements of loop quantum gravity is the consistent quantization of the analog of the Wheeler-DeWitt equation which is free of ultraviolet divergences. However, ambiguities associated to the intermediate regularization procedure lead to an apparently infinite set of possible theories. The absence of an UV problem--the existence of well-behaved regularization of the constraints--is intimately linked with the ambiguities arising in the quantum theory. Among these ambiguities is the one associated to the SU(2) unitary representation used in the diffeomorphism covariant 'point-splitting' regularization of the nonlinear functionals of the connection. This ambiguity is labeled by a half-integer m and, here, it is referred to as the m ambiguity. The aim of this paper is to investigate the important implications of this ambiguity. We first study 2+1 gravity (and more generally BF theory) quantized in the canonical formulation of loop quantum gravity. Only when the regularization of the quantum constraints is performed in terms of the fundamental representation of the gauge group does one obtain the usual topological quantum field theory as a result. In all other cases unphysical local degrees of freedom arise at the level of the regulated theory that conspire against the existence of the continuum limit. This shows that there is a clear-cut choice in the quantization of the constraints in 2+1 loop quantum gravity. We then analyze the effects of the ambiguity in 3+1 gravity exhibiting the existence of spurious solutions for higher representation quantizations of the Hamiltonian constraint. Although the analysis is not complete in 3+1 dimensions - due to the difficulties associated to the definition of the physical inner product - it provides evidence supporting the definitions quantum dynamics of loop quantum gravity in terms of the fundamental representation of the gauge group as the only consistent possibilities. If the gauge group is SO(3) we find

  14. Some Problems for Representations of Brain Organization Based on Activation in Functional Imaging

    Science.gov (United States)

    Sidtis, John J.

    2007-01-01

    Functional brain imaging has overshadowed traditional lesion studies in becoming the dominant approach to the study of brain-behavior relationships. The proponents of functional imaging studies frequently argue that this approach provides an advantage over lesion studies by observing normal brain activity in vivo without the disruptive effects of…

  15. Ambiguities in thermoluminescence dosimetry

    International Nuclear Information System (INIS)

    On one hand, thermoluminescence dosimetry is one of most reliable, rugged and economical system of passive dosimetry but on the other hand there are several ambiguities, which need attention. The PTTL is a complex phenomenon and it is difficult to identify the source for the transfer of the charge carrier to repopulate the traps related to the glow peaks. For the photon energy dependence it is difficult to explain the change in the response for 662 keV gamma rays of 137Cs as compared to the response for 1.25 MeV gamma rays of 60Co. The increase in the response of a TLD with increasing heating rate poses another ambiguity and so is the case with the observations of the supra linearity of different glow peaks. To over come the ambiguities, efforts have to continue to enhance the understanding and to harmonize the protocol for reliable experimental data

  16. Lexical ambiguity resolution

    Energy Technology Data Exchange (ETDEWEB)

    Small, S.; Cottrell, G.; Tanenhaus, M.

    1987-01-01

    This book collects much of the best research currently available on the problem of lexical ambiguity resolution in the processing of human language. When taken out of context, sentences are usually ambiguous. When actually uttered in a dialogue or written in text, these same sentences often have unique interpretations. The inherent ambiguity of isolated sentences, becomes obvious in the attempt to write a computer program to understand them. Different views have emerged on the nature of context and the mechanisms by which it directs unambiguous understanding of words and sentences. These perspectives are represented and discussed. Eighteen original papers from a valuable source book for cognitive scientists in AI, psycholinguistics, neuropsychology, or theoretical linguistics.

  17. A continuous semantic space describes the representation of thousands of object and action categories across the human brain.

    Science.gov (United States)

    Huth, Alexander G; Nishimoto, Shinji; Vu, An T; Gallant, Jack L

    2012-12-20

    Humans can see and name thousands of distinct object and action categories, so it is unlikely that each category is represented in a distinct brain area. A more efficient scheme would be to represent categories as locations in a continuous semantic space mapped smoothly across the cortical surface. To search for such a space, we used fMRI to measure human brain activity evoked by natural movies. We then used voxelwise models to examine the cortical representation of 1,705 object and action categories. The first few dimensions of the underlying semantic space were recovered from the fit models by principal components analysis. Projection of the recovered semantic space onto cortical flat maps shows that semantic selectivity is organized into smooth gradients that cover much of visual and nonvisual cortex. Furthermore, both the recovered semantic space and the cortical organization of the space are shared across different individuals.

  18. A continuous semantic space describes the representation of thousands of object and action categories across the human brain.

    Science.gov (United States)

    Huth, Alexander G; Nishimoto, Shinji; Vu, An T; Gallant, Jack L

    2012-12-20

    Humans can see and name thousands of distinct object and action categories, so it is unlikely that each category is represented in a distinct brain area. A more efficient scheme would be to represent categories as locations in a continuous semantic space mapped smoothly across the cortical surface. To search for such a space, we used fMRI to measure human brain activity evoked by natural movies. We then used voxelwise models to examine the cortical representation of 1,705 object and action categories. The first few dimensions of the underlying semantic space were recovered from the fit models by principal components analysis. Projection of the recovered semantic space onto cortical flat maps shows that semantic selectivity is organized into smooth gradients that cover much of visual and nonvisual cortex. Furthermore, both the recovered semantic space and the cortical organization of the space are shared across different individuals. PMID:23259955

  19. Ambiguity in urban belonging

    DEFF Research Database (Denmark)

    Koefoed, Lasse Martin; Simonsen, Kirsten

    2015-01-01

    mapping of life as an ethnic minority in the city. It revolves around three issues. First, it focuses on the narrators’ experiences of exclusions and blockages in everyday life. This is followed by a focus on urban belonging emphasizing its differential character. Finally, the ambiguity of experiences...

  20. An ambiguous relationship

    DEFF Research Database (Denmark)

    Søndergaard Larsen, Lene; Hedegaard Larsen, Birte; Birkelund, Regner

    2013-01-01

    and volunteered participation. Typically, the social interaction was experienced as giving and was referred to in positive terms but recurrently, the opposite was experienced too. The ambiguity of the relationship clearly emerged in all of the synthesized themes presented in this article. Implications...

  1. An ambiguous relationship

    DEFF Research Database (Denmark)

    Andersen, Lene Søndergaard; Larsen, Birte Hedegaard; Birkelund, Regner

    2013-01-01

    . Typically, the social interaction was experienced as giving and was referred to in positive terms but recurrently, the opposite was experienced too. The ambiguity of the relationship clearly emerged in all of the synthesized themes presented in this article. Implications for practice: Hospitalized patients...

  2. Representational similarity encoding for fMRI: Pattern-based synthesis to predict brain activity using stimulus-model-similarities.

    Science.gov (United States)

    Anderson, Andrew James; Zinszer, Benjamin D; Raizada, Rajeev D S

    2016-03-01

    Patterns of neural activity are systematically elicited as the brain experiences categorical stimuli and a major challenge is to understand what these patterns represent. Two influential approaches, hitherto treated as separate analyses, have targeted this problem by using model-representations of stimuli to interpret the corresponding neural activity patterns. Stimulus-model-based-encoding synthesizes neural activity patterns by first training weights to map between stimulus-model features and voxels. This allows novel model-stimuli to be mapped into voxel space, and hence the strength of the model to be assessed by comparing predicted against observed neural activity. Representational Similarity Analysis (RSA) assesses models by testing how well the grand structure of pattern-similarities measured between all pairs of model-stimuli aligns with the same structure computed from neural activity patterns. RSA does not require model fitting, but also does not allow synthesis of neural activity patterns, thereby limiting its applicability. We introduce a new approach, representational similarity-encoding, that builds on the strengths of RSA and robustly enables stimulus-model-based neural encoding without model fitting. The approach therefore sidesteps problems associated with overfitting that notoriously confront any approach requiring parameter estimation (and is consequently low cost computationally), and importantly enables encoding analyses to be incorporated within the wider Representational Similarity Analysis framework. We illustrate this new approach by using it to synthesize and decode fMRI patterns representing the meanings of words, and discuss its potential biological relevance to encoding in semantic memory. Our new similarity-based encoding approach unites the two previously disparate methods of encoding models and RSA, capturing the strengths of both, and enabling similarity-based synthesis of predicted fMRI patterns.

  3. Semantic ambiguity processing in sentence context : Evidence from event-related fMRI

    NARCIS (Netherlands)

    Zempleni, Monika-Zita; Renken, Remco; Hoeks, John C. J.; Hoogduin, Johannes M.; Stowe, Laurie A.

    2007-01-01

    Lexical semantic ambiguity is the phenomenon when a word has multiple meanings (e.g. 'bank'). The aim of this event-related functional MRI study was to identify those brain areas, which are involved in contextually driven ambiguity resolution. Ambiguous words were selected which have a most frequent

  4. To mind the mind: An event-related potential study of word class and semantic ambiguity

    OpenAIRE

    Lee, Chia-Lin; Federmeier, Kara D.

    2006-01-01

    The goal of this study was to jointly examine the effects of word class, word class ambiguity, and semantic ambiguity on the brain response to words in syntactically specified contexts. Four types of words were used: (1) word class ambiguous words with a high degree of semantic ambiguity (e.g., ‘duck’); (2) word class ambiguous words with little or no semantic ambiguity (e.g., ‘vote’); (3) word class unambiguous nouns (e.g., ‘sofa’); and (4) word class unambiguous verbs (e.g., ‘eat’). These w...

  5. Right-sided representational neglect after left brain damage in a case without visuospatial working memory deficits.

    Science.gov (United States)

    van Dijck, Jean-Philippe; Gevers, Wim; Lafosse, Christophe; Fias, Wim

    2013-10-01

    Brain damaged patients suffering from representational neglect (RN) fail to report, orient to, or verbally describe contra-lesional elements of imagined environments or objects. So far this disorder has only been reported after right brain damage, leading to the idea that only the right hemisphere is involved in this deficit. A widely accepted account attributes RN to a lateralized impairment in the visuospatial component of working memory. So far, however, this hypothesis has not been tested in detail. In the present paper, we describe, for the first time, the case of a left brain damaged patient suffering from right-sided RN while imagining both known and new environments and objects. An in-depth evaluation of her visuospatial working memory abilities, with special focus on the presence of a lateralized deficit, did not reveal any abnormality. In sharp contrast, her ability to memorize visual information was severely compromised. The implications of these results are discussed in the light of recent insights in the neglect syndrome.

  6. Quantum Entropic Ambiguities: Ethylene

    CERN Document Server

    Balachandran, A P; Vaidya, S

    2013-01-01

    In a quantum system, there may be many density matrices associated with a state on an algebra of observables. For each density matrix, one can compute its entropy. These are in general different. Therefore one reaches the remarkable possibility that there may be many entropies for a given state [Private communication from R. Sorkin]. This ambiguity in entropy can often be traced to a gauge symmetry emergent from the non-trivial topological character of the configuration space of the underlying system. It can also happen in finite-dimensional matrix models. In the present work, we discuss this entropy ambiguity and its consequences for an ethylene molecule. This is a very simple and well-known system where these notions can be put to tests. Besides its intrinsic conceptual interest, the simplicity of this model can serve as an introduction to a similar discussion of systems such as coloured monopoles and the breaking of colour symmetry.

  7. Ambiguity in language networks

    CERN Document Server

    Solé, Ricard V

    2014-01-01

    Human language defines the most complex outcomes of evolution. The emergence of such an elaborated form of communication allowed humans to create extremely structured societies and manage symbols at different levels including, among others, semantics. All linguistic levels have to deal with an astronomic combinatorial potential that stems from the recursive nature of languages. This recursiveness is indeed a key defining trait. However, not all words are equally combined nor frequent. In breaking the symmetry between less and more often used and between less and more meaning-bearing units, universal scaling laws arise. Such laws, common to all human languages, appear on different stages from word inventories to networks of interacting words. Among these seemingly universal traits exhibited by language networks, ambiguity appears to be a specially relevant component. Ambiguity is avoided in most computational approaches to language processing, and yet it seems to be a crucial element of language architecture. ...

  8. Facing ambiguous threats.

    Science.gov (United States)

    Roberto, Michael A; Bohmer, Richard M J; Edmondson, Amy C

    2006-11-01

    On February 1, 2003, the world watched in horror as the Columbia space shuttle broke apart while reentering the earth's atmosphere, killing all seven astronauts. Some have argued that NASA's failure to respond with appropriate intensity to the so-called foam strike that led to the accident was evidence of irresponsible or incompetent management. The authors' research, however, suggests that NASA was exhibiting a natural, albeit unfortunate, pattern of behavior common in many organizations. The foam strike is a prime example of what the authors call an ambiguous threat-a signal that may or may not portend future harm. Ambiguous threats differ from threats with obvious causes-say, a fire in the building-for which the response is clear. They also differ from unmistakable threats that may lack straightforward response paths (such as the frightening oxygen-tank explosion aboard Apollo 13). However, when the warning sign is ambiguous and the threat's potential effect is unclear, managers may choose to ignore or discount the risk. Such an approach can be catastrophic. Firms that do a good job of dealing with ambiguous threats do not improvise during a crisis; rather, they apply a rigorous set of detection and response capabilities that they have developed and practiced beforehand. In this article, the authors outline how to put such capabilities in place long before a crisis strikes. First, companies need to hone their teamwork and rapid problem-solving skills through practice. Second, they must learn to recognize weak signals, amplify the threat, and encourage employees to ask disconcerting "what if" questions in a safe environment. Finally, they should explore possible responses to threats through quick, low-cost experimentation. PMID:17131567

  9. Representation and control in closed-loop brain-machine interface systems

    OpenAIRE

    Moorman, Helene

    2015-01-01

    Brain-machine interface (BMI) systems attempt to restore motor function lost due to injury or neurodegenerative disease by bypassing natural motor pathways and allowing direct neural control of a movement actuator. Such systems also hold promise for investigating questions about learning and motor control in a highly controlled and observable system. Here we utilize a BMI paradigm in which single unit neural spiking activity recorded from motor cortical areas in non-human primates is used to ...

  10. Localization of brain activities using multiway analysis of EEG tensor via EMD and reassigned TF representation.

    Science.gov (United States)

    Pouryazdian, Saeed; Beheshti, Soosan; Krishnan, Sridhar

    2015-01-01

    Electroencephalogram (EEG) is widely used for monitoring, diagnosis purposes and also for study of brain's physiological, mental and functional abnormalities. Processing of information by the brain is reflected in dynamical changes of the electrical activity in time, frequency, and space. EEG signal processing tends to describe and quantify these variations in such a way that they are localized in temporal, spectral and spatial domain. Here we use multi-way (Tensor) analysis for localizing the EEG events. We used EMD process for decomposing EEG into distinct oscillatory modes, which are then mapped to TF plane using the near optimal Reassigned Spectrogram. Temporal, Spatial and Spectral information of the Multichannel EEG are then used to generate a three-way Frequency-Time-Space EEG tensor. Exploiting EMD also enables us to detrend the EEG recordings. Simulation results on both synthetic and real EEG data show that tensor analysis greatly improve separation and localization of overlapping events in EEG and it could be effectively exploited for detecting and characterizing the evoked potentials.

  11. Neuroimaging studies of bilingual expressive language representation in the brain: potential applications for magnetoencephalography

    Institute of Scientific and Technical Information of China (English)

    Elizabeth W.Pang

    2012-01-01

    Bilingualism is the ability to use two or more languages with equal or near equal fluency.How the brain,often seamlessly,selects,controls,and switches between languages is an enigma.Neuroimaging studies offer the unique opportunity to probe the mechanisms underlying bilingual brain function.Non-invasive methods,in particular,functional MRI (fMRI) and event-related potentials (ERPs),have allowed examination in healthy control populations.Whole-head magnetoencephalography (MEG),a relatively new addition to the cadre of neuroimaging tools,offers a combination of the high spatial resolution of fMRI with the high temporal resolution of ERPs.Thus far,MEG has been applied to the studies of bilingual receptive language,or bilingual language comprehension.MEG has not yet been applied to the study of bilingual language production as such studies have faced more challenges (see Salmelin,2007 for a review),and these have only recently been addressed.Here,we review the literature on MEG expressive language studies and point out a direction for the application of MEG to the study of bilingual language production.

  12. Instrument specific brain activation in sensorimotor and auditory representation in musicians.

    Science.gov (United States)

    Gebel, B; Braun, Ch; Kaza, E; Altenmüller, E; Lotze, M

    2013-07-01

    Musicians show a remarkable ability to interconnect motor patterns and sensory processing in the somatosensory and auditory domains. Many of these processes are specific for the instrument used. We were interested in the cerebral and cerebellar representations of these instrument-specific changes and therefore applied functional magnetic resonance imaging (fMRI) in two groups of instrumentalists with different instrumental training for comparable periods (approximately 15 years). The first group (trumpet players) uses tight finger and lip interaction; the second (pianists as control group) uses only the extremities for performance. fMRI tasks were balanced for instructions (piano and trumpet notes), sensory feedback (keypad and trumpet), and hand-lip interaction on the trumpet. During fMRI, both groups switched between different devices (trumpet or keypad) and performance was combined with or without auditory feedback. Playing the trumpet without any tone emission or using the mouthpiece showed an instrument training-specific activation increase in trumpet players. This was evident for the posterior-superior cerebellar hemisphere, the dominant primary sensorimotor cortex, and the left Heschl's gyrus. Additionally, trumpet players showed increased activity in the bilateral Heschl's gyrus during actual trumpet playing, although they showed significantly decreased loudness while playing with the mouthpiece in the scanner compared to pianists. PMID:23454048

  13. Translation Ambiguity but Not Word Class Predicts Translation Performance

    Science.gov (United States)

    Prior, Anat; Kroll, Judith F.; Macwhinney, Brian

    2013-01-01

    We investigated the influence of word class and translation ambiguity on cross-linguistic representation and processing. Bilingual speakers of English and Spanish performed translation production and translation recognition tasks on nouns and verbs in both languages. Words either had a single translation or more than one translation. Translation…

  14. Long-term priming of the meanings of ambiguous words

    Science.gov (United States)

    Rodd, Jennifer M.; Lopez Cutrin, Belen; Kirsch, Hannah; Millar, Allesandra; Davis, Matthew H.

    2013-01-01

    Comprehension of semantically ambiguous words (e.g., "bark") is strongly influenced by the relative frequencies of their meanings, such that listeners are biased towards retrieving the most frequent meaning. These biases are often assumed to reflect a highly stable property of an individual's long-term lexical-semantic representations. We present…

  15. The Development of Hand-Centered Visual Representations in the Primate Brain: A Computer Modeling Study Using Natural Visual Scenes.

    Science.gov (United States)

    Galeazzi, Juan M; Minini, Loredana; Stringer, Simon M

    2015-01-01

    Neurons that respond to visual targets in a hand-centered frame of reference have been found within various areas of the primate brain. We investigate how hand-centered visual representations may develop in a neural network model of the primate visual system called VisNet, when the model is trained on images of the hand seen against natural visual scenes. The simulations show how such neurons may develop through a biologically plausible process of unsupervised competitive learning and self-organization. In an advance on our previous work, the visual scenes consisted of multiple targets presented simultaneously with respect to the hand. Three experiments are presented. First, VisNet was trained with computerized images consisting of a realistic image of a hand and a variety of natural objects, presented in different textured backgrounds during training. The network was then tested with just one textured object near the hand in order to verify if the output cells were capable of building hand-centered representations with a single localized receptive field. We explain the underlying principles of the statistical decoupling that allows the output cells of the network to develop single localized receptive fields even when the network is trained with multiple objects. In a second simulation we examined how some of the cells with hand-centered receptive fields decreased their shape selectivity and started responding to a localized region of hand-centered space as the number of objects presented in overlapping locations during training increases. Lastly, we explored the same learning principles training the network with natural visual scenes collected by volunteers. These results provide an important step in showing how single, localized, hand-centered receptive fields could emerge under more ecologically realistic visual training conditions.

  16. The development of hand-centred visual representations in the primate brain: a computer modelling study using natural visual scenes.

    Directory of Open Access Journals (Sweden)

    Juan Manuel Galeazzi

    2015-12-01

    Full Text Available Neurons that respond to visual targets in a hand-centred frame of reference have been found within various areas of the primate brain. We investigate how hand-centred visual representations may develop in a neural network model of the primate visual system called VisNet, when the model is trained on images of the hand seen against natural visual scenes. The simulations show how such neurons may develop through a biologically plausible process of unsupervised competitive learning and self-organisation. In an advance on our previous work, the visual scenes consisted of multiple targets presented simultaneously with respect to the hand. Three experiments are presented. First, VisNet was trained with computerized images consisting of a realistic image of a hand and and a variety of natural objects, presented in different textured backgrounds during training. The network was then tested with just one textured object near the hand in order to verify if the output cells were capable of building hand-centered representations with a single localised receptive field. We explain the underlying principles of the statistical decoupling that allows the output cells of the network to develop single localised receptive fields even when the network is trained with multiple objects. In a second simulation we examined how some of the cells with hand-centred receptive fields decreased their shape selectivity and started responding to a localised region of hand-centred space as the number of objects presented in overlapping locations during training increases. Lastly, we explored the same learning principles training the network with natural visual scenes collected by volunteers. These results provide an important step in showing how single, localised, hand-centered receptive fields could emerge under more ecologically realistic visual training conditions.

  17. The Development of Hand-Centered Visual Representations in the Primate Brain: A Computer Modeling Study Using Natural Visual Scenes.

    Science.gov (United States)

    Galeazzi, Juan M; Minini, Loredana; Stringer, Simon M

    2015-01-01

    Neurons that respond to visual targets in a hand-centered frame of reference have been found within various areas of the primate brain. We investigate how hand-centered visual representations may develop in a neural network model of the primate visual system called VisNet, when the model is trained on images of the hand seen against natural visual scenes. The simulations show how such neurons may develop through a biologically plausible process of unsupervised competitive learning and self-organization. In an advance on our previous work, the visual scenes consisted of multiple targets presented simultaneously with respect to the hand. Three experiments are presented. First, VisNet was trained with computerized images consisting of a realistic image of a hand and a variety of natural objects, presented in different textured backgrounds during training. The network was then tested with just one textured object near the hand in order to verify if the output cells were capable of building hand-centered representations with a single localized receptive field. We explain the underlying principles of the statistical decoupling that allows the output cells of the network to develop single localized receptive fields even when the network is trained with multiple objects. In a second simulation we examined how some of the cells with hand-centered receptive fields decreased their shape selectivity and started responding to a localized region of hand-centered space as the number of objects presented in overlapping locations during training increases. Lastly, we explored the same learning principles training the network with natural visual scenes collected by volunteers. These results provide an important step in showing how single, localized, hand-centered receptive fields could emerge under more ecologically realistic visual training conditions. PMID:26696876

  18. Ambiguous symbols: why there were no figurines in Neolithic Britain

    Directory of Open Access Journals (Sweden)

    Julian Thomas

    2005-12-01

    Full Text Available In this paper I discuss the scarcity of representational art, and particularly of representations of the human body, in Neolithic Britain, in contrast with the Neolithic of south-east Europe. My suggestion is that this contrast can be linked with differing notions of personal identity and bodily integrity. In later Neolithic Britain, a complex mode of non-representational decoration developed, which elaborated the practice of making reference to absent persons and things by using deliberately ambiguous motifs, which connected past and present as well as remote locations.

  19. Phonetic Ambiguity Approaches, Touchstones, Pitfalls and New Approaches

    CERN Document Server

    Juola, P

    1996-01-01

    Phonetic ambiguity and confusibility are bugbears for any form of bottom-up or data-driven approach to language processing. The question of when an input is ``close enough'' to a target word pervades the entire problem spaces of speech recognition, synthesis, language acquisition, speech compression, and language representation, but the variety of representations that have been applied are demonstrably inadequate to at least some aspects of the problem. This paper reviews this inadequacy by examining several touchstone models in phonetic ambiguity and relating them to the problems they were designed to solve. An good solution would be, among other things, efficient, accurate, precise, and universally applicable to representation of words, ideally usable as a ``phonetic distance'' metric for direct measurement of the ``distance'' between word or utterance pairs. None of the proposed models can provide a complete solution to the problem; in general, there is no algorithmic theory of phonetic distance. It is unc...

  20. De morseir syndrome presenting as ambiguous genitalia

    Directory of Open Access Journals (Sweden)

    Anubhav Thukral

    2012-01-01

    Full Text Available Background: A 10-year-old boy presented with genital ambiguity, poor linear growth, and delayed milestones. The aim and to highlight that although rare but congenital, hypogonadotropic hypogonadism may rarely present as ambiguity. Materials and Methods: The patient was found to have bilateral cryptorchidism with proximal penile hypospadias, microphallus with a proportionate dwarfism with mildly delayed bone age, and karyotype 46XY. Euthyroid with normal steroid axis, growth hormone insufficient as suggested by auxology, low IGF1, and poor response to clonidine stimulation. MRI brain shows hypoplastic corpus callosum, hypoplastic anterior pituitary, and ectopic posterior pituitary bright spot. Results: The patient underwent laparoscopic removal of right intrabdominal testis and orchidoplexy was performed on the left one. Testicular biopsy revealed no malignancy and growth hormone replacement was initiated. The patient awaits definitive repair of hypospadias. Conclusion: As a provisional diagnosis of combined growth hormone and gonadotropin deficiency, most probable diagnosis is septo-optic dysplasia or de moseir syndrome leading to genital ambiguity.

  1. Strategic ambiguity in minority targeting

    NARCIS (Netherlands)

    S. Puntoni (Stefano); J. Vanhamme (Joëlle); R. Visscher (Ruben)

    2012-01-01

    textabstractAmbiguous cues in advertising offer companies the chance to reach multiple consumer segments with the one economical campaign. ‘Purposeful polysemy’ can indeed be an effective strategy – but it may not always deliver what it promises.

  2. Alcohol reduces aversion to ambiguity

    Directory of Open Access Journals (Sweden)

    Tadeusz eTyszka

    2015-01-01

    Full Text Available Several years ago, Cohen, Dearnaley, and Hansel [1] demonstrated that under the influence of alcohol drivers became more risk prone, although their risk perception remained unchanged. Research shows that ambiguity aversion is to some extent positively correlated with risk aversion, though not very highly [2]. The question addressed by the present research is whether alcohol reduces ambiguity aversion. Our research was conducted in a natural setting (a restaurant bar, where customers with differing levels of alcohol intoxication were offered a choice between a risky and an ambiguous lottery. We found that alcohol reduced ambiguity aversion and that the effect occurred in men but not women. We interpret these findings in terms of the risk-as-value hypothesis, according to which, people in Western culture tend to value risk, and suggest that alcohol consumption triggers adherence to socially and culturally valued patterns of conduct different for men and women.

  3. Plutonium disproportionation: the ambiguity phenomenon.

    Science.gov (United States)

    Silver, G L

    2003-05-01

    Plutonium oxidation-state studies may yield ambiguous results if the parameters are not carefully chosen. The effect can be related to environmental plutonium as illustrated by an example. PMID:12735968

  4. Lexical and Syntactic Representations in the Brain: An fMRI Investigation with Multi-Voxel Pattern Analyses

    Science.gov (United States)

    Fedorenko, Evelina; Nieto-Castanon, Alfonso; Kanwisher, Nancy

    2012-01-01

    Work in theoretical linguistics and psycholinguistics suggests that human linguistic knowledge forms a continuum between individual lexical items and abstract syntactic representations, with most linguistic representations falling between the two extremes and taking the form of lexical items stored together with the syntactic/semantic contexts in…

  5. Human Perception of Ambiguous Inertial Motion Cues

    Science.gov (United States)

    Zhang, Guan-Lu

    2010-01-01

    Human daily activities on Earth involve motions that elicit both tilt and translation components of the head (i.e. gazing and locomotion). With otolith cues alone, tilt and translation can be ambiguous since both motions can potentially displace the otolithic membrane by the same magnitude and direction. Transitions between gravity environments (i.e. Earth, microgravity and lunar) have demonstrated to alter the functions of the vestibular system and exacerbate the ambiguity between tilt and translational motion cues. Symptoms of motion sickness and spatial disorientation can impair human performances during critical mission phases. Specifically, Space Shuttle landing records show that particular cases of tilt-translation illusions have impaired the performance of seasoned commanders. This sensorimotor condition is one of many operational risks that may have dire implications on future human space exploration missions. The neural strategy with which the human central nervous system distinguishes ambiguous inertial motion cues remains the subject of intense research. A prevailing theory in the neuroscience field proposes that the human brain is able to formulate a neural internal model of ambiguous motion cues such that tilt and translation components can be perceptually decomposed in order to elicit the appropriate bodily response. The present work uses this theory, known as the GIF resolution hypothesis, as the framework for experimental hypothesis. Specifically, two novel motion paradigms are employed to validate the neural capacity of ambiguous inertial motion decomposition in ground-based human subjects. The experimental setup involves the Tilt-Translation Sled at Neuroscience Laboratory of NASA JSC. This two degree-of-freedom motion system is able to tilt subjects in the pitch plane and translate the subject along the fore-aft axis. Perception data will be gathered through subject verbal reports. Preliminary analysis of perceptual data does not indicate that

  6. The Ambiguity in Who Goes with Fergus

    Institute of Scientific and Technical Information of China (English)

    卿丽园

    2015-01-01

    Yeats is one of the most distinguished Irish poets. In poem Who Goes with Fergus displays his ambiguous attitude to the imagined nature and chaotic Irish society. Based on Empson’s ambiguity theory, the paper is to analyze the ambiguity art of the poem and get the conclusion that its ambiguity is due to Yeats’ambivalent spirit and mind.

  7. A Brief Discussion of eliminating Grammatical Ambiguity

    Institute of Scientific and Technical Information of China (English)

    张俊

    2014-01-01

    As we all know that one kind of language structure has more than one meaning,to be called ambiguity.Generally thought,the grammatical ambiguity is quite complex in English,and this article pays attention to eliminating English grammatical ambiguity and making the shallow analysis on the three kinds of strategies of eliminating ambiguity.

  8. On the Spatial Ambiguity Function

    CERN Document Server

    Yuryev, Arthur N

    2014-01-01

    The ambiguity function of a spatial signal in the "signal spatial frequency displacement vs antenna linear displacement" coordinates is considered in this paper; in case of a monochromatic signal with known carrier frequency, spatial signal vector angular displacement is considered as the second coordinate. The analysis is made taking into account an external (reradiated or thermal) background which contributes considerable peculiarities in the properties of the spatial ambiguity function. Accuracy of measuring the signal linear or angular displacement and resolution are determined. Examples for the Fresnel and Fraunhofer zones are given.

  9. Hierarchical Morphological Structure and Ambiguity

    DEFF Research Database (Denmark)

    Vikner, Carl; Vikner, Sten

    2008-01-01

    English has a number of adjectives of the type unXable, adjectives that contain the prefix un- and the adjectivising suffix -able, e.g. unlockable or undoable. Many of these adjectives are ambiguous. If a door is unlockable, it may either mean that it cannot be locked (it is not lockable), as exp......English has a number of adjectives of the type unXable, adjectives that contain the prefix un- and the adjectivising suffix -able, e.g. unlockable or undoable. Many of these adjectives are ambiguous. If a door is unlockable, it may either mean that it cannot be locked (it is not lockable...

  10. GRAPES-Grounding representations in action, perception, and emotion systems: How object properties and categories are represented in the human brain.

    Science.gov (United States)

    Martin, Alex

    2016-08-01

    In this article, I discuss some of the latest functional neuroimaging findings on the organization of object concepts in the human brain. I argue that these data provide strong support for viewing concepts as the products of highly interactive neural circuits grounded in the action, perception, and emotion systems. The nodes of these circuits are defined by regions representing specific object properties (e.g., form, color, and motion) and thus are property-specific, rather than strictly modality-specific. How these circuits are modified by external and internal environmental demands, the distinction between representational content and format, and the grounding of abstract social concepts are also discussed. PMID:25968087

  11. Symbol in View of Ambiguity

    Directory of Open Access Journals (Sweden)

    Mohamad reza Yousefi

    2013-11-01

    Full Text Available Abstract Symbol from the perspective of rhetorical word, is phrase or sentence that apparent meaning, also inspires to reader a wide range of semantic.Since exploring the complex social and political ideas in the most mysticalway and indirectreflectionsocial and political thoughts symbolically is easier, so the symbol and symbolism especially in Persian literatureespeciallyin the realm of Persian poetry, has a special appearance.In addition to the factors mentioned in the contemporary literature, according familiar in literature and the emergence of particular schools interest toambiguoussymbolization has spreadfurther, especially the symbol has all the features of art ambiguity in the poem and it isone the major factors causing uncertainty.Thus, the precise definitions and symbols of contemporary poetry could be dominant in the unwinding ambiguous symbol detection of cryptic allusions and metaphors that matches the cursor symbol to help readers.  In the literature, especially language poetry, the inability of language toreflecting obscure mystical ideas, avoid to directexpression of political and social concerns of the reader in the course of participate to creation ambiguous literary works is the main motivation towards symbol and symbolization.According widespread use of symbol and its different of species can be viewed from different perspectives.The creation of ambiguity is the main purposes of using symbols (especially in poetry, so many poets have tried to achieve this goal have to formation of similar symbols and the explanation and resolution of this issue can open new window for understanding the poetry in front of an audience.  In this paper examines the ambiguity of symbols in terms of its precise boundaries are reviewed. Ambiguity is one of the important processes and also is the key Iranian poetry its means is today poetry. In such poetry ambiguity is a need to explore the new world from a different perspective, or explore this

  12. Brain

    Science.gov (United States)

    ... will return after updating. Resources Archived Modules Updates Brain Cerebrum The cerebrum is the part of the ... the outside of the brain and spinal cord. Brain Stem The brain stem is the part of ...

  13. Spectral Ambiguity of Allan Variance

    Science.gov (United States)

    Greenhall, C. A.

    1996-01-01

    We study the extent to which knowledge of Allan variance and other finite-difference variances determines the spectrum of a random process. The variance of first differences is known to determine the spectrum. We show that, in general, the Allan variance does not. A complete description of the ambiguity is given.

  14. The Decimal Representation of Real Numbers

    Science.gov (United States)

    Kalapodi, A.

    2010-01-01

    The representation of natural numbers in decimal form is an unequivocal procedure while for the representation of real numbers some ambiguities concerning the existence of infinitely many digits equal to 9 still emerge. One of the most frequently confronted misunderstandings is whether 0.999...equals 1 or not, and if not what number does this…

  15. Searching for the best model: ambiguity of inverse solutions and application to fetal magnetoencephalography

    Energy Technology Data Exchange (ETDEWEB)

    Vrba, J [VSM MedTech Ltd, Coquitlam, BC, V3K 7B2 (Canada); Robinson, S E [VSM MedTech Ltd, Coquitlam, BC, V3K 7B2 (Canada); McCubbin, J [Department of Obstetrics and Gynecology, University of Arkansas for Medical Sciences, Little Rock, AR 72205 (United States); Lowery, C L [Department of Obstetrics and Gynecology, University of Arkansas for Medical Sciences, Little Rock, AR 72205 (United States); Eswaran, H [Department of Obstetrics and Gynecology, University of Arkansas for Medical Sciences, Little Rock, AR 72205 (United States); Murphy, P [Department of Obstetrics and Gynecology, University of Arkansas for Medical Sciences, Little Rock, AR 72205 (United States); Preissl, H [Department of Obstetrics and Gynecology, University of Arkansas for Medical Sciences, Little Rock, AR 72205 (United States)

    2007-02-07

    Fetal brain signals produce weak magnetic fields at the maternal abdominal surface. In the presence of much stronger interference these weak fetal fields are often nearly indistinguishable from noise. Our initial objective was to validate these weak fetal brain fields by demonstrating that they agree with the electromagnetic model of the fetal brain. The fetal brain model is often not known and we have attempted to fit the data to not only the brain source position, orientation and magnitude, but also to the brain model position. Simulation tests of this extended model search on fetal MEG recordings using dipole fit and beamformers revealed a region of ambiguity. The region of ambiguity consists of a family of models which are not distinguishable in the presence of noise, and which exhibit large and comparable SNR when beamformers are used. Unlike the uncertainty of a dipole fit with known model plus noise, this extended ambiguity region yields nearly identical forward solutions, and is only weakly dependent on noise. The ambiguity region is located in a plane defined by the source position, orientation, and the true model centre, and will have a diameter approximately 0.67 of the modelled fetal head diameter. Existence of the ambiguity region allows us to only state that the fetal brain fields do not contradict the electromagnetic model; we can associate them with a family of models belonging to the ambiguity region, but not with any specific model. In addition to providing a level of confidence in the fetal brain signals, the ambiguity region knowledge in combination with beamformers allows detection of undistorted temporal waveforms with improved signal-to-noise ratio, even though the source position cannot be uniquely determined.

  16. Distinct representations of configural and part information across multiple face-selective regions of the human brain

    OpenAIRE

    Golarai, Golijeh; Ghahremani, Dara G.; Eberhardt, Jennifer L.; John D E Gabrieli

    2015-01-01

    Several regions of the human brain respond more strongly to faces than to other visual stimuli, such as regions in the amygdala (AMG), superior temporal sulcus (STS), and the fusiform face area (FFA). It is unclear if these brain regions are similar in representing the configuration or natural appearance of face parts. We used functional magnetic resonance imaging of healthy adults who viewed natural or schematic faces with internal parts that were either normally configured or randomly rearr...

  17. Ambiguity Resolution in English Language Processing

    Institute of Scientific and Technical Information of China (English)

    唐慧君; 黄曦

    2013-01-01

    Language ambiguity resolution has been widely studied by psycholinguists. Studies of lexical ambiguity resolution, syn⁃tactic ambiguity resolution and anaphoric ambiguity resolution have showed different results. One account assumes that ambigui⁃ty resolution involves“competition”of analysis which causes processing difficulties. The other account claims that an initial analy⁃sis is adopt and“reanalysis”occurs when the initial analysis turns out to be implausible.

  18. Towards Multimodal Content Representation

    CERN Document Server

    Bunt, Harry

    2009-01-01

    Multimodal interfaces, combining the use of speech, graphics, gestures, and facial expressions in input and output, promise to provide new possibilities to deal with information in more effective and efficient ways, supporting for instance: - the understanding of possibly imprecise, partial or ambiguous multimodal input; - the generation of coordinated, cohesive, and coherent multimodal presentations; - the management of multimodal interaction (e.g., task completion, adapting the interface, error prevention) by representing and exploiting models of the user, the domain, the task, the interactive context, and the media (e.g. text, audio, video). The present document is intended to support the discussion on multimodal content representation, its possible objectives and basic constraints, and how the definition of a generic representation framework for multimodal content representation may be approached. It takes into account the results of the Dagstuhl workshop, in particular those of the informal working group...

  19. Ambiguity Aversion and Variance Premium

    OpenAIRE

    Jianjun Miao; Bin Wei; Hao Zhou

    2012-01-01

    This paper offers an ambiguity-based interpretation of variance premium - the differ- ence between risk-neutral and objective expectations of market return variance - as a com- pounding effect of both belief distortion and variance differential regarding the uncertain economic regimes. Our approach endogenously generates variance premium without impos- ing exogenous stochastic volatility or jumps in consumption process. Such a framework can reasonably match the mean variance premium as well a...

  20. Updating representations of temporal intervals.

    Science.gov (United States)

    Danckert, James; Anderson, Britt

    2015-12-01

    Effectively engaging with the world depends on accurate representations of the regularities that make up that world-what we call mental models. The success of any mental model depends on the ability to adapt to changes-to 'update' the model. In prior work, we have shown that damage to the right hemisphere of the brain impairs the ability to update mental models across a range of tasks. Given the disparate nature of the tasks we have employed in this prior work (i.e. statistical learning, language acquisition, position priming, perceptual ambiguity, strategic game play), we propose that a cognitive module important for updating mental representations should be generic, in the sense that it is invoked across multiple cognitive and perceptual domains. To date, the majority of our tasks have been visual in nature. Given the ubiquity and import of temporal information in sensory experience, we examined the ability to build and update mental models of time. We had healthy individuals complete a temporal prediction task in which intervals were initially drawn from one temporal range before an unannounced switch to a different range of intervals. Separate groups had the second range of intervals switch to one that contained either longer or shorter intervals than the first range. Both groups showed significant positive correlations between perceptual and prediction accuracy. While each group updated mental models of temporal intervals, those exposed to shorter intervals did so more efficiently. Our results support the notion of generic capacity to update regularities in the environment-in this instance based on temporal information. The task developed here is well suited to investigations in neurological patients and in neuroimaging settings. PMID:26303026

  1. Context sensitivity and ambiguity in component-based systems design

    Energy Technology Data Exchange (ETDEWEB)

    Bespalko, S.J.; Sindt, A.

    1997-10-01

    Designers of components-based, real-time systems need to guarantee to correctness of soft-ware and its output. Complexity of a system, and thus the propensity for error, is best characterized by the number of states a component can encounter. In many cases, large numbers of states arise where the processing is highly dependent on context. In these cases, states are often missed, leading to errors. The following are proposals for compactly specifying system states which allow the factoring of complex components into a control module and a semantic processing module. Further, the need for methods that allow for the explicit representation of ambiguity and uncertainty in the design of components is discussed. Presented herein are examples of real-world problems which are highly context-sensitive or are inherently ambiguous.

  2. NEW ALGORITHM FOR FAST INTEGER AMBIGUITY RESOLUTION

    Institute of Scientific and Technical Information of China (English)

    HEXiao-feng; HUXiao-ping

    2005-01-01

    Fast integer ambiguity resolution is referred as a key part in precision relative positioning of the GPS carrier phase. A new algorithm for fast integer ambiguity resolution based on LAMBDA and FASF methods is proposed. This algorithm integrates the LAMBDA method and the FASF method, thus improving the efficiency of the ambiguity resolution. Firstly, the ambiguity search space transformation in the LAMBDA method is used,and then the FASF method is used to search ambiguities. Experiments in the relative positioning of about 1 km static baseline demonstrate that the error is less than 1 cm.

  3. Review of Sparse Representation-Based Classification Methods on EEG Signal Processing for Epilepsy Detection, Brain-Computer Interface and Cognitive Impairment

    Science.gov (United States)

    Wen, Dong; Jia, Peilei; Lian, Qiusheng; Zhou, Yanhong; Lu, Chengbiao

    2016-01-01

    At present, the sparse representation-based classification (SRC) has become an important approach in electroencephalograph (EEG) signal analysis, by which the data is sparsely represented on the basis of a fixed dictionary or learned dictionary and classified based on the reconstruction criteria. SRC methods have been used to analyze the EEG signals of epilepsy, cognitive impairment and brain computer interface (BCI), which made rapid progress including the improvement in computational accuracy, efficiency and robustness. However, these methods have deficiencies in real-time performance, generalization ability and the dependence of labeled sample in the analysis of the EEG signals. This mini review described the advantages and disadvantages of the SRC methods in the EEG signal analysis with the expectation that these methods can provide the better tools for analyzing EEG signals. PMID:27458376

  4. Review of Sparse Representation-Based Classification Methods on EEG Signal Processing for Epilepsy Detection, Brain-Computer Interface and Cognitive Impairment.

    Science.gov (United States)

    Wen, Dong; Jia, Peilei; Lian, Qiusheng; Zhou, Yanhong; Lu, Chengbiao

    2016-01-01

    At present, the sparse representation-based classification (SRC) has become an important approach in electroencephalograph (EEG) signal analysis, by which the data is sparsely represented on the basis of a fixed dictionary or learned dictionary and classified based on the reconstruction criteria. SRC methods have been used to analyze the EEG signals of epilepsy, cognitive impairment and brain computer interface (BCI), which made rapid progress including the improvement in computational accuracy, efficiency and robustness. However, these methods have deficiencies in real-time performance, generalization ability and the dependence of labeled sample in the analysis of the EEG signals. This mini review described the advantages and disadvantages of the SRC methods in the EEG signal analysis with the expectation that these methods can provide the better tools for analyzing EEG signals.

  5. The ambiguous challenge of intranets

    DEFF Research Database (Denmark)

    Thommesen, Jacob

    2003-01-01

    increases with tendencies to cooperate and communicate across organisational boundaries, mainly as a reaction to developments in markets and industrial knowledge base, but also due to the potential provided by computer network. In the third chapter I identify some characteristics of two fundamental intranet...... media, email and the web, partly in the perspective of media richness theory, partly compared with philosophical discussions of classical media. The fourth chapter presents an intranet in a global company, in which problems and challenges related to ambiguity have proven significant....

  6. From “Where” to “What”: Distributed Representations of Brand Associations in the Human Brain

    Science.gov (United States)

    Chen, Yu-Ping; Nelson, Leif D.; Hsu, Ming

    2015-01-01

    Considerable attention has been given to the notion that there exists a set of human-like characteristics associated with brands, referred to as brand personality. Here we combine newly available machine learning techniques with functional neuroimaging data to characterize the set of processes that give rise to these associations. We show that brand personality traits can be captured by the weighted activity across a widely distributed set of brain regions previously implicated in reasoning, imagery, and affective processing. That is, as opposed to being constructed via reflective processes, brand personality traits appear to exist a priori inside the minds of consumers, such that we were able to predict what brand a person is thinking about based solely on the relationship between brand personality associations and brain activity. These findings represent an important advance in the application of neuroscientific methods to consumer research, moving from work focused on cataloguing brain regions associated with marketing stimuli to testing and refining mental constructs central to theories of consumer behavior. PMID:27065490

  7. Anxiety and Outcome Evaluation: The Good, the Bad and the Ambiguous

    OpenAIRE

    Gu, Ruolei; Ge, Yue; Jiang, Yang; Luo, Yue-jia

    2010-01-01

    Previous research has indicated that anxious individuals are more prone to evaluate ambiguous information as negative compared to non-anxious individuals. The feedback-related negativity (FRN) component of event-related brain potential (ERP) has been shown to be sensitive to outcome evaluation. The current ERP study aimed to test the hypothesis that the FRNs associated with ambiguous outcomes and negative outcomes are different between high trait-anxiety (HTA) and low trait-anxiety (LTA) indi...

  8. Rocking or rolling--perception of ambiguous motion after returning from space.

    Directory of Open Access Journals (Sweden)

    Gilles Clément

    Full Text Available The central nervous system must resolve the ambiguity of inertial motion sensory cues in order to derive an accurate representation of spatial orientation. Adaptive changes during spaceflight in how the brain integrates vestibular cues with other sensory information can lead to impaired movement coordination, vertigo, spatial disorientation, and perceptual illusions after return to Earth. The purpose of this study was to compare tilt and translation motion perception in astronauts before and after returning from spaceflight. We hypothesized that these stimuli would be the most ambiguous in the low-frequency range (i.e., at about 0.3 Hz where the linear acceleration can be interpreted either as a translation or as a tilt relative to gravity. Verbal reports were obtained in eleven astronauts tested using a motion-based tilt-translation device and a variable radius centrifuge before and after flying for two weeks on board the Space Shuttle. Consistent with previous studies, roll tilt perception was overestimated shortly after spaceflight and then recovered with 1-2 days. During dynamic linear acceleration (0.15-0.6 Hz, ±1.7 m/s2 perception of translation was also overestimated immediately after flight. Recovery to baseline was observed after 2 days for lateral translation and 8 days for fore-aft translation. These results suggest that there was a shift in the frequency dynamic of tilt-translation motion perception after adaptation to weightlessness. These results have implications for manual control during landing of a space vehicle after exposure to microgravity, as it will be the case for human asteroid and Mars missions.

  9. How meaning similarity influences ambiguous word processing: the current state of the literature.

    Science.gov (United States)

    Eddington, Chelsea M; Tokowicz, Natasha

    2015-02-01

    The majority of words in the English language do not correspond to a single meaning, but rather correspond to two or more unrelated meanings (i.e., are homonyms) or multiple related senses (i.e., are polysemes). It has been proposed that the different types of "semantically-ambiguous words" (i.e., words with more than one meaning) are processed and represented differently in the human mind. Several review papers and books have been written on the subject of semantic ambiguity (e.g., Adriaens, Small, Cottrell, & Tanenhaus, 1988; Burgess & Simpson, 1988; Degani & Tokowicz, 2010; Gorfein, 1989, 2001; Simpson, 1984). However, several more recent studies (e.g., Klein & Murphy, 2001; Klepousniotou, 2002; Klepousniotou & Baum, 2007; Rodd, Gaskell, & Marslen-Wilson, 2002) have investigated the role of the semantic similarity between the multiple meanings of ambiguous words on processing and representation, whereas this was not the emphasis of previous reviews of the literature. In this review, we focus on the current state of the semantic ambiguity literature that examines how different types of ambiguous words influence processing and representation. We analyze the consistent and inconsistent findings reported in the literature and how factors such as semantic similarity, meaning/sense frequency, task, timing, and modality affect ambiguous word processing. We discuss the findings with respect to recent parallel distributed processing (PDP) models of ambiguity processing (Armstrong & Plaut, 2008, 2011; Rodd, Gaskell, & Marslen-Wilson, 2004). Finally, we discuss how experience/instance-based models (e.g., Hintzman, 1986; Reichle & Perfetti, 2003) can inform a comprehensive understanding of semantic ambiguity resolution. PMID:24889119

  10. Ambiguity in Keats’s Lamia

    Directory of Open Access Journals (Sweden)

    Chunhong Yang

    2014-10-01

    Full Text Available Keats’s Lamia is usually read as an ambiguous poem. The paper will focus on the causes of Lamia’s ambiguity. Her ambiguity presents Keats’s vacillation between two poetic realms—the beautiful and the sublime. And the poem tries to offer his solution to his dilemma. While Wordsworth prefers the sublime in Tintern Abbey and Intimations on Immortality, Keats offers a different choice in Lamia.

  11. Primordial function and ambiguity in its determination

    CERN Document Server

    Petrov, V K

    2003-01-01

    We study the possibility to reconstruct the primordial function for some periodic function. The procedure includes an analytical continuation of a discrete function for Fourier coefficients computation, that introduces an ambiguity. To establish conditions under which no ambiguity appears, the modification of Carlson theorem is suggested. In a case when no subsidiary condition is imposed, ambiguity in the definition of primordial function does not go beyond the functions which belong to space $\\Omega^{\\prime}$.

  12. Power and optimism : interpreting ambiguous information

    OpenAIRE

    Cobb, Lindsey Erin

    2011-01-01

    Interpreting ambiguous statements is a common and inescapable aspect of everyday life. Previous research suggests that elevated power leads to the optimistic interpretation of ambiguous information while diminished power leads to the pessimistic interpretation of ambiguous information. However, empirical evidence does not speak to situations that are (1) absent of rewards or punishments and (2) operate at a high cognitive level. The current investigation attempts to address this empirical gap...

  13. Effective ambiguity checking in biosequence analysis

    Directory of Open Access Journals (Sweden)

    Giegerich Robert

    2005-06-01

    Full Text Available Abstract Background Ambiguity is a problem in biosequence analysis that arises in various analysis tasks solved via dynamic programming, and in particular, in the modeling of families of RNA secondary structures with stochastic context free grammars. Several types of analysis are invalidated by the presence of ambiguity. As this problem inherits undecidability (as we show here from the namely problem for context free languages, there is no complete algorithmic solution to the problem of ambiguity checking. Results We explain frequently observed sources of ambiguity, and show how to avoid them. We suggest four testing procedures that may help to detect ambiguity when present, including a just-in-time test that permits to work safely with a potentially ambiguous grammar. We introduce, for the special case of stochastic context free grammars and RNA structure modeling, an automated partial procedure for proving non-ambiguity. It is used to demonstrate non-ambiguity for several relevant grammars. Conclusion Our mechanical proof procedure and our testing methods provide a powerful arsenal of methods to ensure non-ambiguity.

  14. Harmonic Training and the formation of pitch representation in a neural network model of the auditory brain

    Directory of Open Access Journals (Sweden)

    Nasir eAhmad

    2016-03-01

    Full Text Available Attempting to explain the perceptual qualities of pitch has proven to be, and remains, a difficult problem. The wide range of sounds which illicit pitch and a lack of agreement across neurophysiological studies on how pitch is encoded by the brain have made this attempt more difficult. In describing the potential neural mechanisms by which pitch may be processed, a number of neural networks have been proposed and implemented. However, no unsupervised neural networks with biologically accurate cochlear inputs have yet been demonstrated. This paper proposes a simplified system in which pitch representing neurons are easily produced under a highly biological setting. Purely unsupervised regimes of neural network learning are implemented and these prove to be sufficient in identifying the pitch of sounds with a variety of spectral profiles, including missing fundamental sounds.

  15. Roles of frontal and temporal regions in reinterpreting semantically ambiguous sentences

    Directory of Open Access Journals (Sweden)

    Sylvia eVitello

    2014-07-01

    Full Text Available Semantic ambiguity resolution is an essential and frequent part of speech comprehension because many words map onto multiple meanings (e.g., bark, bank. Neuroimaging research highlights the importance of the left inferior frontal gyrus (LIFG and the left posterior temporal cortex in this process but the roles they serve in ambiguity resolution are uncertain. One possibility is that both regions are engaged in the processes of semantic reinterpretation that follows incorrect interpretation of an ambiguous word. Here we used fMRI to investigate this hypothesis. 20 native British English monolinguals were scanned whilst listening to sentences that contained an ambiguous word. To induce semantic reinterpretation, the disambiguating information was presented after the ambiguous word and delayed until the end of the sentence (e.g., the teacher explained that the BARK was going to be very damp. These sentences were compared to well-matched unambiguous sentences. Supporting the reinterpretation hypothesis, these ambiguous sentences produced more activation in both the LIFG and the left posterior inferior temporal cortex. Importantly, all but one subject showed ambiguity-related peaks within both regions, demonstrating that the group-level results were driven by high inter-subject consistency. Further support came from the finding that activation in both regions was modulated by meaning dominance. Specifically, sentences containing biased ambiguous words, which have one more dominant meaning, produced greater activation than those with balanced ambiguous words, which have two equally frequent meanings. Because the context always supported the less frequent meaning, the biased words require reinterpretation more often than balanced words. This is the first evidence of dominance effects in the spoken modality and provides strong support that frontal and temporal regions support the updating of semantic representations during speech comprehension.

  16. Roles of frontal and temporal regions in reinterpreting semantically ambiguous sentences.

    Science.gov (United States)

    Vitello, Sylvia; Warren, Jane E; Devlin, Joseph T; Rodd, Jennifer M

    2014-01-01

    Semantic ambiguity resolution is an essential and frequent part of speech comprehension because many words map onto multiple meanings (e.g., "bark," "bank"). Neuroimaging research highlights the importance of the left inferior frontal gyrus (LIFG) and the left posterior temporal cortex in this process but the roles they serve in ambiguity resolution are uncertain. One possibility is that both regions are engaged in the processes of semantic reinterpretation that follows incorrect interpretation of an ambiguous word. Here we used fMRI to investigate this hypothesis. 20 native British English monolinguals were scanned whilst listening to sentences that contained an ambiguous word. To induce semantic reinterpretation, the disambiguating information was presented after the ambiguous word and delayed until the end of the sentence (e.g., "the teacher explained that the BARK was going to be very damp"). These sentences were compared to well-matched unambiguous sentences. Supporting the reinterpretation hypothesis, these ambiguous sentences produced more activation in both the LIFG and the left posterior inferior temporal cortex. Importantly, all but one subject showed ambiguity-related peaks within both regions, demonstrating that the group-level results were driven by high inter-subject consistency. Further support came from the finding that activation in both regions was modulated by meaning dominance. Specifically, sentences containing biased ambiguous words, which have one more dominant meaning, produced greater activation than those with balanced ambiguous words, which have two equally frequent meanings. Because the context always supported the less frequent meaning, the biased words require reinterpretation more often than balanced words. This is the first evidence of dominance effects in the spoken modality and provides strong support that frontal and temporal regions support the updating of semantic representations during speech comprehension. PMID:25120445

  17. Processing subject-object ambiguities in Dutch

    NARCIS (Netherlands)

    Kaan, Edith

    1997-01-01

    Various clause types in Dutch and German are at least temporarily ambiguous with respect to the order of subject and object. A number of previous studies regarding the processing of such subject-object ambiguities have reported a preference for a subject-object interpretation. This order preference

  18. Deliberate ambiguity in slogans: recognition and appreciation

    NARCIS (Netherlands)

    Lagerwerf, Luuk

    2002-01-01

    In slogans used in public information, politics, and advertising, and also in titles of books, documentaries, or articles, ambiguity is often employed to pique the interest of the reader in the message that is conveyed. According to several theories of text processing, this deliberate ambiguity may

  19. Analyzing Ambiguity of Context-Free Grammars

    DEFF Research Database (Denmark)

    Brabrand, Claus; Giegerich, Robert; Møller, Anders

    2010-01-01

    It has been known since 1962 that the ambiguity problem for context-free grammars is undecidable. Ambiguity in context-free grammars is a recurring problem in language design and parser generation, as well as in applications where grammars are used as models of real-world physical structures. We...

  20. Ambiguity and Volatility : Asset Pricing Implications

    NARCIS (Netherlands)

    Pataracchia, B.

    2011-01-01

    Using a simple dynamic consumption-based asset pricing model, this paper explores the implications of a representative investor with smooth ambiguity averse preferences [Klibano¤, Marinacci and Mukerji, Econometrica (2005)] and provides a comparative analysis of risk aversion and ambiguity aversion.

  1. Ambiguous Words Are Harder to Learn

    Science.gov (United States)

    Degani, Tamar; Tokowicz, Natasha

    2010-01-01

    Relatively little is known about the role of ambiguity in adult second-language learning. In this study, native English speakers learned Dutch-English translation pairs that either mapped in a one-to-one fashion (unambiguous items) in that a Dutch word uniquely corresponded to one English word, or mapped in a one-to-many fashion (ambiguous items),…

  2. On Infinite Quon Statistics and "Ambiguous" Statistics

    OpenAIRE

    Meljanac, S.; Milekovic, M.; Ristic, R.

    1999-01-01

    We critically examine a recent suggestion that "ambiguous" statistics is equivalent to infinite quon statistics and that it describes a dilute, nonrelativistics ideal gas of extremal black holes. We show that these two types of statistics are different and that the description of extremal black holes in terms of "ambiguous" statistics cannot be applied.

  3. A toolbox for representational similarity analysis.

    OpenAIRE

    Hamed Nili; Cai Wingfield; Alexander Walther; Li Su; William Marslen-Wilson; Nikolaus Kriegeskorte

    2014-01-01

    Neuronal population codes are increasingly being investigated with multivariate pattern-information analyses. A key challenge is to use measured brain-activity patterns to test computational models of brain information processing. One approach to this problem is representational similarity analysis (RSA), which characterizes a representation in a brain or computational model by the distance matrix of the response patterns elicited by a set of stimuli. The representational distance matrix enca...

  4. A toolbox for representational similarity analysis

    OpenAIRE

    Nili, Hamed; Wingfield, Cai; Walther, Alexander; Su, Li; Marslen-Wilson, William; KRIEGESKORTE, Nikolaus

    2014-01-01

    Neuronal population codes are increasingly being investigated with multivariate pattern-information analyses. A key challenge is to use measured brain-activity patterns to test computational models of brain information processing. One approach to this problem is representational similarity analysis (RSA), which characterizes a representation in a brain or computational model by the distance matrix of the response patterns elicited by a set of stimuli. The representational distance matrix enca...

  5. Rational Expectations Equilibria: Existence and Representation

    OpenAIRE

    Bhowmik, Anuj; Cao, Jiling

    2015-01-01

    In this paper, we continue to explore the equilibrium theory under ambiguity. For a model of a pure exchange and asymmetric information economy with a measure space of agents whose exogenous uncertainty is described by a complete probability space, we establish a representation theorem for a Bayesian or maximin rational expectations equilibrium allocation in terms of a state-wise Walrasian equilibrium allocation. This result also strengthens the theorems on the existence and representation of...

  6. Ambiguity noise analysis of a SAR system

    Science.gov (United States)

    Tian, Haishan; Chang, Wenge; Li, Xiangyang

    2015-12-01

    The presence of range and azimuth (or Doppler) ambiguities in synthetic aperture radars (SARs) is well known. The ambiguity noise is related to the antenna pattern and the value of pulse repetition frequency (PRF). Because a new frequency modulated continuous wave (FMCW) SAR has the characters of low cost and small size, and the capacity of real-time signal processing, the antenna will likely vibrate or deform due to a lack of the stabilized platform. And the value of PRF cannot be much high because of the high computation burden for the real-time processing. The aim of this study is to access and improve the performance of a new FMCW SAR system based on the ambiguity noise. First, the quantitative analysis of the system's ambiguity noise level is performed; an antenna with low sidelobes is designed. The conclusion is that the range ambiguity noise is small; the azimuth ambiguity noise is somewhat increased, however, it is sufficiently small to have marginal influence on the image quality. Finally, the ambiguity noise level is measured using the imaging data from a Ku-band FMCW SAR. The results of this study show that the measured noise level coincides with the theoretical noise level.

  7. Word's vector representations meet machine translation

    OpenAIRE

    Martínez Garcia, Eva; España Bonet, Cristina; Tiedemann, Jörg; Márquez Villodre, Luís

    2014-01-01

    Distributed vector representations of words are useful in various NLP tasks. We briefly review the CBOW approach and propose a bilingual application of this architecture with the aim to improve consistency and coherence of Machine Translation. The primary goal of the bilingual extension is to handle ambiguous words for which the different senses are conflated in the monolingual setup.

  8. Equity Trading under Heterogeneity in Ambiguity

    DEFF Research Database (Denmark)

    Alonso, Irasema; Prado, Mauricio

    -relevant, but hard-to-interpret information: a situation like that during the onset of the recent crisis in financial markets. During this episode, market participants appeared unsure of the values of a variety of assets, trading all but stopped. Ambiguity aversion, it appears to us, offers a tractable way......We examine the potential importance of heterogeneity in consumers' ambiguity aversion for asset pricing, portfolio allocation, and the wealth distribution. A main focus is to explore a situation in which ambiguity aversion is \\above normal", such as when there has been a sudden inflow of market...

  9. Canonical representation for approximating solution of fuzzy polynomial equations

    Directory of Open Access Journals (Sweden)

    M. Salehnegad

    2010-06-01

    Full Text Available In this paper, the concept of canonical representation is proposed to find fuzzy roots of fuzzy polynomial equations. We transform fuzzy polynomial equations to system of crisp polynomial equations, this transformation is perform by using canonical representation based on three parameters Value, Ambiguity and Fuzziness.

  10. A Systemic-Functional Approach to English Ambiguity

    Institute of Scientific and Technical Information of China (English)

    张静

    2014-01-01

    This thesis chooses the theory of rank scale and the theory of meta-function in the framework of Systemic-Functional Grammar (SFG) to study ambiguity. It firstly analyzes ambiguities occurring at the rank of morpheme, word or phrase. Then it studies ambiguities at the rank of clause, from ideational ambiguity to textual ambiguity. This study shows that SFG can give a sys-tematic and comprehensive interpretation of English ambiguity.

  11. Risk Management and Insurance Decisions under Ambiguity

    DEFF Research Database (Denmark)

    Martínez-Correa, Jimmy

    I study the impact of ambiguity on insurance decisions and the optimality of insurance contracts. My tractable approach allows me to study the interaction between risk and ambiguity attitudes. When insurance decisions are made independently of other assets, for a given increase in wealth, both risk...... and ambiguity attitudes interact in nontrivial ways to determine the change of coinsurance demand. I derive sufficient conditions to guarantee that the optimal coinsurance demand is decreasing in wealth. When a non-traded asset is introduced, my model predicts behavior that is inconsistent with the classical...... a counterexample to a classical result in insurance economics where an insurance contract with straight deductible is dominated by a coinsurance contract. Finally, I find that a modified Borch rule characterizes the optimal insurance contract with bilateral risk and ambiguity attitudes and heterogeneity in beliefs....

  12. How to Distinguish Ambiguity and Vagueness

    Institute of Scientific and Technical Information of China (English)

    赵洪石

    2008-01-01

    This thesis mainly deals with the problem about ambiguity and vagueness through the example of‘ease'.The tests of"do so identity"and"sense relation"will be used here to illustrate the distinction of them.

  13. Negotiating Ambiguity: Dynamic Structure in Schoenberg Songs

    OpenAIRE

    Hawes, Vanessa

    2015-01-01

    Background Schoenberg’s Das Buch der Hängenden Gärten (1909) has been the subject of many analytical treatments. Work has focused on the relationship between words and music and on the (a)tonal language. Underpinning both of these historically/philosophically important themes is the ambiguous structure of the songs. Developing an understanding of structure is one way in which a framework is provided for learning music preparation for performance. How do performers negotiate ambiguous st...

  14. Remindings influence the interpretation of ambiguous stimuli

    OpenAIRE

    Tullis, Jonathan G.; Braverman, Michael; Ross, Brian H; Benjamin, Aaron S.

    2014-01-01

    Remindings–stimulus-guided retrievals of prior events–may help us interpret ambiguous events by linking the current situation to relevant prior experiences. Evidence suggests that remindings play an important role in interpreting complex ambiguous stimuli (Ross & Bradshaw, 1994); here we evaluate whether remindings influence word interpretation and memory in a new paradigm. Learners studied words on distinct visual backgrounds and generated a sentence for each word. Homographs were either pre...

  15. Neural responses to category ambiguous words

    OpenAIRE

    Conwell, Erin

    2015-01-01

    Category ambiguous words (like hug and swing) have the potential to complicate both learning and processing of language. However, uses of such words may be disambiguated by acoustic differences that depend on the category of use. This article uses an event-related potential (ERP) technique to ask whether adult native speakers of English show neural sensitivity to those differences. The results indicate that noun and verb tokens of ambiguous words produce differences in the amplitude of the ER...

  16. Ambiguities and Image Quality in Staggered SAR

    OpenAIRE

    Villano, Michelangelo; Krieger, Gerhard; Moreira, Alberto

    2015-01-01

    Staggered SAR is an innovative synthetic aperture radar (SAR) concept, where the pulse repetition interval (PRI) is continuously varied. This, together with digital beamforming (DBF) in elevation, allows high-resolution imaging of a wide continuous swath without the need for a long antenna with multiple azimuth apertures. As an additional benefit, the energy of range and azimuth ambiguities is spread over large areas: Ambiguities therefore appear in the image as a noise-like disturbance rathe...

  17. A Method to Identify Potential Ambiguous Malay Words Through Ambiguity Attributes Mapping: An Exploratory Study

    Directory of Open Access Journals (Sweden)

    Hazlina Haron

    2014-02-01

    Full Text Available We describe here a methodology to identify a list o f ambiguous Malay words that are commonly being used in Malay documentations such as Requirem ent Specification. We compiled several relevant and appropriate requirement quality attrib utes and sentence rules from previous literatures and adopt it to come out with a set of ambiguity attributes that most suit Malay words. The extracted Malay ambiguous words (potenti al are then being mapped onto the constructed ambiguity attributes to confirm their v agueness. The list is then verified by Malay linguist experts. This paper aims to identify a lis t of potential ambiguous words in Malay as an attempt to assist writers to avoid using the vague words while documenting Malay Requirement Specification as well as to any other related Malay documentation. The result of this study is a list of 120 potential ambiguous Malay words that co uld act as guidelines in writing Malay sentences.

  18. Recommendations for reducing ambiguity in written procedures.

    Energy Technology Data Exchange (ETDEWEB)

    Matzen, Laura E.

    2009-11-01

    Previous studies in the nuclear weapons complex have shown that ambiguous work instructions (WIs) and operating procedures (OPs) can lead to human error, which is a major cause for concern. This report outlines some of the sources of ambiguity in written English and describes three recommendations for reducing ambiguity in WIs and OPs. The recommendations are based on commonly used research techniques in the fields of linguistics and cognitive psychology. The first recommendation is to gather empirical data that can be used to improve the recommended word lists that are provided to technical writers. The second recommendation is to have a review in which new WIs and OPs and checked for ambiguities and clarity. The third recommendation is to use self-paced reading time studies to identify any remaining ambiguities before the new WIs and OPs are put into use. If these three steps are followed for new WIs and OPs, the likelihood of human errors related to ambiguity could be greatly reduced.

  19. Theory of Carrier Phase Ambiguity Resolution

    Institute of Scientific and Technical Information of China (English)

    P. J. G. Teunissen

    2003-01-01

    Carrier phase ambiguity resolution is the key to high precision Global Navigation Satellite System(GNSS) positioning and navigation. It applies to a great variety of current and future models of GPS, modernized GPS and Galileo. A proper handling of carrier phase ambiguity resolution requires a proper understanding of the underlying theory of integer inference. In this contribution a brief review is given of the probabilistic theory of integer ambiguity estimation. We describe the concept of ambiguity pull-in regions, introduce the class of admissible integer estimators, determine their probability mass functions and show how their variability solution. The theory is worked out in more detail for integer least-squares and integer bootstrapping. It is shown that the integer least-squares principle maximizes the probability of correct integer estimation. Sharp and easy-to-compute bounds are given for both the ambiguity success rate and the baseline's probability of concentration. Finally the probability density function of the ambiguity residuals is determined. This allows one for the first time to formulate rigorous tests for the integerness of the parameters.

  20. A method to identify potential ambiguous Malay words through Ambiguity Attributes mapping: An exploratory Study

    OpenAIRE

    Hazlina Haron; Abdul Azim Abd Ghani

    2014-01-01

    We describe here a methodology to identify a list o f ambiguous Malay words that are commonly being used in Malay documentations such as Requirem ent Specification. We compiled several relevant and appropriate requirement quality attrib utes and sentence rules from previous literatures and adopt it to come out with a set of ambiguity attributes that most suit Malay words. The extracted Malay ambiguous words (potenti al)...

  1. Poetic representation

    DEFF Research Database (Denmark)

    Wulf-Andersen, Trine Østergaard

    2012-01-01

    , and dialogue, of situated participants. The article includes a lengthy example of a poetic representation of one participant’s story, and the author comments on the potentials of ‘doing’ poetic representations as an example of writing in ways that challenges what sometimes goes unasked in participative social...... be written up and disseminated. The article takes a methodological focus, considering general aims and methods of the research project, before turning to the elaboration on how poetic representations have been constructed and employed as a vehicle for certain kinds of participation, representation...

  2. Clarity and ambiguity in psychoanalytic practice.

    Science.gov (United States)

    Szajnberg, Nathan

    2011-03-01

    The author explores the presence and the essential tension between clarity and ambiguity as processes within our minds that become prominent in psychoanalysis. We learn from aesthetics and literary criticism that ambiguity can shade from taut disorganization to tolerating life's richness; clarity can range from a concrete fixity to a lucid grasp of one's state of mind. This article responds to Wallerstein's (1991) challenge to find common ground in psychoanalytic practice: We attempt this by avoiding metapsychological jargon and relying on more experience-near terms, such as clarity and ambiguity. The article also refers to Sandler's (1983) concept of implicit theory-that psychoanalysts use "preconscious, overlapping but not fully integrated models" (Sandler, 1988, p. 388)-in this case explicating how clarity and ambiguity are frequent but implicit phenomena in clinical work. Identifying these and the essential tension between them permits us to both improve training and identify our clinical efforts. The analyst's and analysand's tolerance of the tension between clarity and ambiguity facilitates increased structuralization and emotional robustness. PMID:21500957

  3. Role ambiguity among school principals in China and Finland

    OpenAIRE

    Li, Lin

    2012-01-01

    This study explores the role-ambiguity phenomenon among public secondary school principals in China and Finland. Organizational dysfunction caused by role ambiguity in professional organizations has been studied since the 1960s (Kahn et al, 1964). Although role ambiguity occurs most frequently in educational organizations, few studies on role ambiguity are found on school leaders. This study contributes to this topic by building a multidimensional knowledge structure of role ambiguity amon...

  4. RELATION OF COACHING BEHAVIOR AND ROLE AMBIGUITY

    Directory of Open Access Journals (Sweden)

    Karamousalidis G.

    2010-08-01

    Full Text Available The purpose of this research was to investigate the relationship between coaching behavior and role ambiguity in defensive responsibilities using interdependent Greek sport teams. Athlete perceptions of role ambiguity (defense were assessed using a questionnaire developed by Beauchamp, Bray, Eys and Carron (2002 andcoaching behavior was assessed using the Coaching Behavior Questionnaire, (Williams, et. al., 2003. The sample consisted of 409 athletes of basketball, volleyball, handball and soccer. Confirmatory factor analysis provided the construct validity of the questionnaires and correlations among the scales confirmed construct validity. The implications of the results are discussed and future research should continue to investigate the multidimensional models of both coaching behavior and role ambiguity in sport settings.

  5. Symbol in Point View of Ambiguity

    Directory of Open Access Journals (Sweden)

    Dr. M. R. Yousefi

    Full Text Available Symbol from the perspective of rhetorical word, is phrase or sentence that apparent meaning, also inspires to reader a wide range of semantic.Since exploring the complex social and political ideas in the most mysticalway and indirectreflectionsocial and political thoughts symbolically is easier, so the symbol and symbolism especially in Persian literatureespeciallyin the realm of Persian poetry, has a special appearance.In addition to the factors mentioned in the contemporary literature, according familiar in literature and the emergence of particular schools interest toambiguoussymbolization has spreadfurther, especially the symbol has all the features of art ambiguity in the poem and it isone the major factors causing uncertainty.Thus, the precise definitions and symbols of contemporary poetry could be dominant in the unwinding ambiguous symbol detection of cryptic allusions and metaphors that matches the cursor symbol to help readers.In the literature, especially language poetry, the inability of language toreflecting obscure mystical ideas, avoid to directexpression of political and social concerns of the reader in the course of participate to creation ambiguous literary works is the main motivation towards symbol and symbolization.According widespread use of symbol and its different of species can be viewed from different perspectives.The creation of ambiguity is the main purposes of using symbols (especially in poetry, so many poets have tried to achieve this goal have to formation of similar symbols and the explanation and resolution of this issue can open new window for understanding the poetry in front of an audience.In this paper examines the ambiguity of symbols in terms of its precise boundaries are reviewed. Ambiguity is one of the important processes and also is the key Iranian poetry; its means is today poetry. In such poetry ambiguity is a need to explore the new world from a different perspective, or explore this complex world

  6. Separable responses to error, ambiguity, and reaction time in cingulo-opercular task control regions.

    Science.gov (United States)

    Neta, Maital; Schlaggar, Bradley L; Petersen, Steven E

    2014-10-01

    The dorsal anterior cingulate (dACC), along with the closely affiliated anterior insula/frontal operculum, have been demonstrated to show three types of task control signals across a wide variety of tasks. One of these signals, a transient signal that is thought to represent performance feedback, shows greater activity to error than correct trials. Other work has found similar effects for uncertainty/ambiguity or conflict, though some argue that dACC activity is, instead, modulated primarily by other processes more reflected in reaction time. Here, we demonstrate that, rather than a single explanation, multiple information processing operations are crucial to characterizing the function of these brain regions, by comparing operations within a single paradigm. Participants performed two tasks in an fMRI experimental session: (1) deciding whether or not visually presented word pairs rhyme, and (2) rating auditorily presented single words as abstract or concrete. A pilot was used to identify ambiguous stimuli for both tasks (e.g., word pair: BASS/GRACE; single word: CHANGE). We found greater cingulo-opercular activity for errors and ambiguous trials than clear/correct trials, with a robust effect of reaction time. The effects of error and ambiguity remained when reaction time was regressed out, although the differences decreased. Further stepwise regression of response consensus (agreement across participants for each stimulus; a proxy for ambiguity) decreased differences between ambiguous and clear trials, but left error-related differences almost completely intact. These observations suggest that trial-wise responses in cingulo-opercular regions monitor multiple performance indices, including accuracy, ambiguity, and reaction time. PMID:24887509

  7. The Ambiguous Role of Constraints in Creativity

    DEFF Research Database (Denmark)

    Biskjær, Michael Mose; Onarheim, Balder; Wiltschnig, Stefan

    2011-01-01

    The relationship between creativity and constraints is often described in the literature either in rather imprecise, general concepts or in relation to very specific domains. Cross-domain and cross-disciplinary takes on how the handling of constraints influences creative activities are rare. In t......-disciplinary research into the ambiguous role of constraints in creativity....

  8. Value Representations

    DEFF Research Database (Denmark)

    Rasmussen, Majken Kirkegaard; Petersen, Marianne Graves

    2011-01-01

    the perspective brings valuable insights on different approaches to technology, but instead to view gender through a value lens. Contributing to this perspective, we have developed Value Representations as a design-oriented instrument for staging a reflective dialogue with users. Value Representations...... are fictional, value-driven concepts developed to promote dialogue with users about their values and how they may materialize with respect to interaction design in their everyday lives....

  9. Quadri-stability of a spatially ambiguous auditory illusion

    Directory of Open Access Journals (Sweden)

    Constance May Bainbridge

    2015-01-01

    Full Text Available In addition to vision, audition plays an important role in sound localization in our world. One way we estimate the motion of an auditory object moving towards or away from us is from changes in volume intensity. However, the human auditory system has unequally distributed spatial resolution, including difficulty distinguishing sounds in front versus behind the listener. Here, we introduce a novel quadri-stable illusion, the Transverse-and-Bounce Auditory Illusion, which combines front-back confusion with changes in volume levels of a nonspatial sound to create ambiguous percepts of an object approaching and withdrawing from the listener. The sound can be perceived as traveling transversely from front to back or back to front, or bouncing to remain exclusively in front of or behind the observer. Here we demonstrate how human listeners experience this illusory phenomenon by comparing ambiguous and unambiguous stimuli for each of the four possible motion percepts. When asked to rate their confidence in perceiving each sound’s motion, participants reported equal confidence for the illusory and unambiguous stimuli. Participants perceived all four illusory motion percepts, and could not distinguish the illusion from the unambiguous stimuli. These results show that this illusion is effectively quadri-stable. In a second experiment, the illusory stimulus was looped continuously in headphones while participants identified its perceived path of motion to test properties of perceptual switching, locking, and biases. Participants were biased towards perceiving transverse compared to bouncing paths, and they became perceptually locked into alternating between front-to-back and back-to-front percepts, perhaps reflecting how auditory objects commonly move in the real world. This multi-stable auditory illusion opens opportunities for studying the perceptual, cognitive, and neural representation of objects in motion, as well as exploring multimodal perceptual

  10. Comment on Lexical Ambiguity in Understanding of the Language

    Institute of Scientific and Technical Information of China (English)

    杨楠

    2013-01-01

    Ambiguity is a natural property of language and may happen anywhere. This paper aims to present a detailed analysis of one of these types:the lexical ambiguity, which exerts great influence on the understanding in communications.

  11. Social representations and contextual adjustments as two distinct components of the Theory of Mind brain network: Evidence from the REMICS task.

    Science.gov (United States)

    Lavoie, Marie-Audrey; Vistoli, Damien; Sutliff, Stephanie; Jackson, Philip L; Achim, Amélie M

    2016-08-01

    Theory of mind (ToM) refers to the ability to infer the mental states of others. Behavioral measures of ToM usually present information about both a character and the context in which this character is placed, and these different pieces of information can be used to infer the character's mental states. A set of brain regions designated as the ToM brain network is recognized to support (ToM) inferences. Different brain regions within that network could however support different ToM processes. This functional magnetic resonance imaging (fMRI) study aimed to distinguish the brain regions supporting two aspects inherent to many ToM tasks, i.e., the ability to infer or represent mental states and the ability to use the context to adjust these inferences. Nineteen healthy subjects were scanned during the REMICS task, a novel task designed to orthogonally manipulate mental state inferences (as opposed to physical inferences) and contextual adjustments of inferences (as opposed to inferences that do not require contextual adjustments). We observed that mental state inferences and contextual adjustments, which are important aspects of most behavioral ToM tasks, rely on distinct brain regions or subregions within the classical brain network activated in previous ToM research. Notably, an interesting dissociation emerged within the medial prefrontal cortex (mPFC) and temporo-parietal junctions (TPJ) such that the inferior part of these brain regions responded to mental state inferences while the superior part of these brain regions responded to the requirement for contextual adjustments. This study provides evidence that the overall set of brain regions activated during ToM tasks supports different processes, and highlights that cognitive processes related to contextual adjustments have an important role in ToM and should be further studied. PMID:27236373

  12. Social representations and contextual adjustments as two distinct components of the Theory of Mind brain network: Evidence from the REMICS task.

    Science.gov (United States)

    Lavoie, Marie-Audrey; Vistoli, Damien; Sutliff, Stephanie; Jackson, Philip L; Achim, Amélie M

    2016-08-01

    Theory of mind (ToM) refers to the ability to infer the mental states of others. Behavioral measures of ToM usually present information about both a character and the context in which this character is placed, and these different pieces of information can be used to infer the character's mental states. A set of brain regions designated as the ToM brain network is recognized to support (ToM) inferences. Different brain regions within that network could however support different ToM processes. This functional magnetic resonance imaging (fMRI) study aimed to distinguish the brain regions supporting two aspects inherent to many ToM tasks, i.e., the ability to infer or represent mental states and the ability to use the context to adjust these inferences. Nineteen healthy subjects were scanned during the REMICS task, a novel task designed to orthogonally manipulate mental state inferences (as opposed to physical inferences) and contextual adjustments of inferences (as opposed to inferences that do not require contextual adjustments). We observed that mental state inferences and contextual adjustments, which are important aspects of most behavioral ToM tasks, rely on distinct brain regions or subregions within the classical brain network activated in previous ToM research. Notably, an interesting dissociation emerged within the medial prefrontal cortex (mPFC) and temporo-parietal junctions (TPJ) such that the inferior part of these brain regions responded to mental state inferences while the superior part of these brain regions responded to the requirement for contextual adjustments. This study provides evidence that the overall set of brain regions activated during ToM tasks supports different processes, and highlights that cognitive processes related to contextual adjustments have an important role in ToM and should be further studied.

  13. Representational Machines

    DEFF Research Database (Denmark)

    Petersson, Dag; Dahlgren, Anna; Vestberg, Nina Lager

    Photography not only represents space. Space is produced photographically. Since its inception in the 19th century, photography has brought to light a vast array of represented subjects. Always situated in some spatial order, photographic representations have been operatively underpinned by social...... to the enterprises of the medium. This is the subject of Representational Machines: How photography enlists the workings of institutional technologies in search of establishing new iconic and social spaces. Together, the contributions to this edited volume span historical epochs, social environments, technological...... possibilities, and genre distinctions. Presenting several distinct ways of producing space photographically, this book opens a new and important field of inquiry for photography research....

  14. Cognitive and Neural Mechanisms Underlying Semantic Ambiguity Resolution

    OpenAIRE

    Vitello, S

    2014-01-01

    The ultimate goal of language comprehension is to obtain meaning. However, this is difficult because many words are semantically ambiguous, mapping onto multiple meanings. Semantic ambiguity resolution has proven a useful tool to investigate language processing in general. However, the majority of research has focused on the initial encounter of an ambiguous word. Less work has investigated the processes occurring after an ambiguous word is encountered, when the initially understood meaning n...

  15. Potential Ambiguity Translation Performances within Legal Language Institutional Nomenclature

    OpenAIRE

    Oţăt Diana

    2015-01-01

    Motivated by a paradoxical corollary of ambiguities in legal documents and especially in contract texts, the current paper underpins a dichotomy approach to unintended ambiguities aiming to establish a referential framework for the occurrence rate of translation ambiguities within the legal language nomenclature. The research focus is on a twofold situation since ambiguities may. on the one hand, arise dining the translation process, generated by the translator’s lack of competence, i.e. inad...

  16. Ambiguities in Quantizing a Classical System

    CERN Document Server

    Redmount, I H; Young, K; Redmount, Ian; Suen, Wai-Mo; Young, Kenneth

    1999-01-01

    One classical theory, as determined by an equation of motion or set of classical trajectories, can correspond to many unitarily {\\em in}equivalent quantum theories upon canonical quantization. This arises from a remarkable ambiguity, not previously investigated, in the construction of the classical (and hence the quantized) Hamiltonian or Lagrangian. This ambiguity is illustrated for systems with one degree of freedom: An arbitrary function of the constants of motion can be introduced into this construction. For example, the nonrelativistic and relativistic free particles follow identical classical trajectories, but the Hamiltonians or Lagrangians, and the canonically quantized versions of these descriptions, are inequivalent. Inequivalent descriptions of other systems, such as the harmonic oscillator, are also readily obtained.

  17. Integration, differentiation and ambiguity in safety cultures

    DEFF Research Database (Denmark)

    Richter, Anne; Koch, Christian

    2004-01-01

    This article discusses safety cultures, drawing on the differentiation, integration and ambiguity-scheme introduced by scholars of organizational culture. An ethnographic approach has been applied in the study of meaning and symbols relating to work, hazards, occupational accidents and prevention....... Although some common elements are present across cultures, they are indeed a multiple configuration of cultures. The article illustrates this by providing one case showing a configuration of three cultures, metaphorically labelled Production, Welfare and Master. For example, the former views risk...

  18. Representation is representation of similarities.

    Science.gov (United States)

    Edelman, S

    1998-08-01

    Advanced perceptual systems are faced with the problem of securing a principled (ideally, veridical) relationship between the world and its internal representation. I propose a unified approach to visual representation, addressing the need for superordinate and basic-level categorization and for the identification of specific instances of familiar categories. According to the proposed theory, a shape is represented internally by the responses of a small number of tuned modules, each broadly selective for some reference shape, whose similarity to the stimulus it measures. This amounts to embedding the stimulus in a low-dimensional proximal shape space spanned by the outputs of the active modules. This shape space supports representations of distal shape similarities that are veridical as Shepard's (1968) second-order isomorphisms (i.e., correspondence between distal and proximal similarities among shapes, rather than between distal shapes and their proximal representations). Representation in terms of similarities to reference shapes supports processing (e.g., discrimination) of shapes that are radically different from the reference ones, without the need for the computationally problematic decomposition into parts required by other theories. Furthermore, a general expression for similarity between two stimuli, based on comparisons to reference shapes, can be used to derive models of perceived similarity ranging from continuous, symmetric, and hierarchical ones, as in multidimensional scaling (Shepard 1980), to discrete and nonhierarchical ones, as in the general contrast models (Shepard & Arabie 1979; Tversky 1977). PMID:10097019

  19. The Psychological Study of Lexical Ambiguity in Reading Comprehension

    Institute of Scientific and Technical Information of China (English)

    魏玥

    2016-01-01

    Lexical ambiguity is the common phenomenon people encounter when they do reading comprehensions. Studying mental decoding process of the ambiguous words helps improve reading instruction skills efficiently. From the perspec-tive of psychology, this thesis tries to analyze the decoding process of lexical ambiguity in reading and raise some sug-gestions for reading instruction.

  20. Remindings influence the interpretation of ambiguous stimuli.

    Science.gov (United States)

    Tullis, Jonathan G; Braverman, Michael; Ross, Brian H; Benjamin, Aaron S

    2014-02-01

    Remindings-stimulus-guided retrievals of prior events-may help us interpret ambiguous events by linking the current situation to relevant prior experiences. Evidence suggests that remindings play an important role in interpreting complex ambiguous stimuli (Ross & Bradshaw Memory & Cognition, 22, 591-605, 1994); here, we evaluate whether remindings will influence word interpretation and memory in a new paradigm. Learners studied words on distinct visual backgrounds and generated a sentence for each word. Homographs were preceded by a biasing cue on the same background three items earlier, preceded by a biasing cue on a different background three items earlier, or followed by a biasing cue on the same background three items later. When biasing cues preceded the homographs on the same backgrounds as the homographs, the meanings of the homographs in learner-generated sentences were consistent with the biasing cues more often than in the other two conditions. These results show that remindings can influence word interpretation. In addition, later memory for the homographs and cues was greater when the meaning of the homograph in the sentence was consistent with the earlier biasing cue, suggesting that remindings enhanced mnemonic performance. Remindings play an important role in how we interpret ambiguous stimuli and enhance memory for the involved material. PMID:23835617

  1. A mixture approach to vagueness and ambiguity.

    Directory of Open Access Journals (Sweden)

    Steven Verheyen

    Full Text Available When asked to indicate which items from a set of candidates belong to a particular natural language category inter-individual differences occur: Individuals disagree which items should be considered category members. The premise of this paper is that these inter-individual differences in semantic categorization reflect both ambiguity and vagueness. Categorization differences are said to be due to ambiguity when individuals employ different criteria for categorization. For instance, individuals may disagree whether hiking or darts is the better example of sports because they emphasize respectively whether an activity is strenuous and whether rules apply. Categorization differences are said to be due to vagueness when individuals employ different cut-offs for separating members from non-members. For instance, the decision to include hiking in the sports category or not, may hinge on how strenuous different individuals require sports to be. This claim is supported by the application of a mixture model to categorization data for eight natural language categories. The mixture model can identify latent groups of categorizers who regard different items likely category members (i.e., ambiguity with categorizers within each of the groups differing in their propensity to provide membership responses (i.e., vagueness. The identified subgroups are shown to emphasize different sets of category attributes when making their categorization decisions.

  2. Simulating Bistable Perception with Interrupted Ambiguous Stimulus using Self-Oscillator Dynamics with Percept Choice Bifurcation

    OpenAIRE

    Fürstenau, N.

    2015-01-01

    A behavioral stochastic self-oscillator model with perception-attention coupling and re-entrant cognitive processing is used for simulating interrupted ambiguous stimulus induced percept reversals. The results provide further support for a dynamical systems foundation of cognitive and psychological problems as discussed in detail within the context of Gestalt psychology [1], and for coordination dynamics of the brain [2]. Periodic stimulus–off switching (toff < 1 s, ton = 300 ms) was introduc...

  3. Memory cueing during sleep modifies the interpretation of ambiguous scenes in adolescents and adults

    OpenAIRE

    Sabine Groch; Dana McMakin; Patrick Guggenbühl; Björn Rasch; Reto Huber; Ines Wilhelm

    2016-01-01

    The individual tendency to interpret ambiguous situations negatively is associated with mental disorders. Interpretation biases are already evident during adolescence and due to the greater plasticity of the developing brain it may be easier to change biases during this time. We investigated in healthy adolescents and adults whether stabilizing memories of positive or negative scenes modulates the later interpretation of similar scenes. In the evening, participants learnt associations between...

  4. A toolbox for representational similarity analysis.

    Directory of Open Access Journals (Sweden)

    Hamed Nili

    2014-04-01

    Full Text Available Neuronal population codes are increasingly being investigated with multivariate pattern-information analyses. A key challenge is to use measured brain-activity patterns to test computational models of brain information processing. One approach to this problem is representational similarity analysis (RSA, which characterizes a representation in a brain or computational model by the distance matrix of the response patterns elicited by a set of stimuli. The representational distance matrix encapsulates what distinctions between stimuli are emphasized and what distinctions are de-emphasized in the representation. A model is tested by comparing the representational distance matrix it predicts to that of a measured brain region. RSA also enables us to compare representations between stages of processing within a given brain or model, between brain and behavioral data, and between individuals and species. Here, we introduce a Matlab toolbox for RSA. The toolbox supports an analysis approach that is simultaneously data- and hypothesis-driven. It is designed to help integrate a wide range of computational models into the analysis of multichannel brain-activity measurements as provided by modern functional imaging and neuronal recording techniques. Tools for visualization and inference enable the user to relate sets of models to sets of brain regions and to statistically test and compare the models using nonparametric inference methods. The toolbox supports searchlight-based RSA, to continuously map a measured brain volume in search of a neuronal population code with a specific geometry. Finally, we introduce the linear-discriminant t value as a measure of representational discriminability that bridges the gap between linear decoding analyses and RSA. In order to demonstrate the capabilities of the toolbox, we apply it to both simulated and real fMRI data. The key functions are equally applicable to other modalities of brain-activity measurement. The

  5. Research on ambiguity resolution aided with triple difference

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The ambiguity resolution in the field of GPS is investigated in detail. A new algorithm to resolve the ambiguity is proposed. The algorithm first obtains the floating resolution of the ambiguity aided with triple difference measurement. Decorrelation of searching space is done by reducing the ambiguity covariance matrix's dimension to overcome the possible sick factorization of the matrix brought by Z-transformation. In simulation, the proposed algorithm is compared with least-squares ambiguity decorrelation adjustment (LAMBDA). The result shows that the proposed algorithm is better than LAMBDA because of lesser resolving time, which approximately reduces 20% resolving time. Thus, the proposed algorithm adapts to the high dynamic real-time applications.

  6. Mapping, filtering and measuring impact of ambiguous words in Portuguese

    OpenAIRE

    Baptista, Jorge; Faísca, Luís

    2007-01-01

    This paper deals with ambiguous simple words of Portuguese. The Portuguese dictionary of simple inflected words contains (DELAF) 936.215 entries, from which there are 889.986 different inflected forms. It is possible to obtain the full list of ambiguous inflected forms (43.126), that is, word forms belonging to different categories and/or lemmas: capital,A/N/N (capital). We may consider A/N/N an ambiguity class. There are 137 ambiguity classes. Each ambiguity class presents a certain level of...

  7. Neural representations of the sense of self

    OpenAIRE

    Klemm, William R.

    2011-01-01

    The brain constructs representations of what is sensed and thought about in the form of nerve impulses that propagate in circuits and network assemblies (Circuit Impulse Patterns, CIPs). CIP representations of which humans are consciously aware occur in the context of a sense of self. Thus, research on mechanisms of consciousness might benefit from a focus on how a conscious sense of self is represented in brain. Like all senses, the sense of self must be contained in patterns of nerve impuls...

  8. Portfolio Management with Stochastic Interest Rates and Inflation Ambiguity

    DEFF Research Database (Denmark)

    Munk, Claus; Rubtsov, Alexey Vladimirovich

    2014-01-01

    We solve, in closed form, a stock-bond-cash portfolio problem of a risk- and ambiguity-averse investor when interest rates and the inflation rate are stochastic. The expected inflation rate is unobservable, but the investor can learn about it from observing realized inflation and stock and bond...... prices. The investor is ambiguous about the inflation model and prefers a portfolio strategy which is robust to model misspecification. Ambiguity about the inflation dynamics is shown to affect the optimal portfolio fundamentally different than ambiguity about the price dynamics of traded assets, for...... example the optimal portfolio weights can be increasing in the degree of ambiguity aversion. In a numerical example, the optimal portfolio is significantly affected by the learning about expected inflation and somewhat affected by ambiguity aversion. The welfare loss from ignoring learning or ambiguity...

  9. Potential Ambiguity Translation Performances within Legal Language Institutional Nomenclature

    Directory of Open Access Journals (Sweden)

    Oţăt Diana

    2015-12-01

    Full Text Available Motivated by a paradoxical corollary of ambiguities in legal documents and especially in contract texts, the current paper underpins a dichotomy approach to unintended ambiguities aiming to establish a referential framework for the occurrence rate of translation ambiguities within the legal language nomenclature. The research focus is on a twofold situation since ambiguities may. on the one hand, arise dining the translation process, generated by the translator’s lack of competence, i.e. inadequate use of English regarding the special nature of legal language, or. on the other hand, they may be simply transferred from the source language into the target language without even noticing the potential ambiguous situation, i.e. culture-bound ambiguities. Hence, the paper proposes a contrastive analysis in order to localize the occurrence of lexical, structural, and socio-cultural ambiguities triggered by the use of the term performance and its Romanian equivalents in a number of sales contracts.

  10. Representational Thickness

    DEFF Research Database (Denmark)

    Mullins, Michael

    Contemporary communicational and informational processes contribute to the shaping of our physical environment by having a powerful influence on the process of design. Applications of virtual reality (VR) are transforming the way architecture is conceived and produced by introducing dynamic...... elements into the process of design. Through its immersive properties, virtual reality allows access to a spatial experience of a computer model very different to both screen based simulations as well as traditional forms of architectural representation. The dissertation focuses on processes of the current...... representation? How is virtual reality used in public participation and how do virtual environments affect participatory decision making? How does VR thus affect the physical world of built environment? Given the practical collaborative possibilities of immersive technology, how can they best be implemented...

  11. Flexible taxonomic assignment of ambiguous sequencing reads

    Directory of Open Access Journals (Sweden)

    Jansson Jesper

    2011-01-01

    Full Text Available Abstract Background To characterize the diversity of bacterial populations in metagenomic studies, sequencing reads need to be accurately assigned to taxonomic units in a given reference taxonomy. Reads that cannot be reliably assigned to a unique leaf in the taxonomy (ambiguous reads are typically assigned to the lowest common ancestor of the set of species that match it. This introduces a potentially severe error in the estimation of bacteria present in the sample due to false positives, since all species in the subtree rooted at the ancestor are implicitly assigned to the read even though many of them may not match it. Results We present a method that maps each read to a node in the taxonomy that minimizes a penalty score while balancing the relevance of precision and recall in the assignment through a parameter q. This mapping can be obtained in time linear in the number of matching sequences, because LCA queries to the reference taxonomy take constant time. When applied to six different metagenomic datasets, our algorithm produces different taxonomic distributions depending on whether coverage or precision is maximized. Including information on the quality of the reads reduces the number of unassigned reads but increases the number of ambiguous reads, stressing the relevance of our method. Finally, two measures of performance are described and results with a set of artificially generated datasets are discussed. Conclusions The assignment strategy of sequencing reads introduced in this paper is a versatile and a quick method to study bacterial communities. The bacterial composition of the analyzed samples can vary significantly depending on how ambiguous reads are assigned depending on the value of the q parameter. Validation of our results in an artificial dataset confirm that a combination of values of q produces the most accurate results.

  12. The Strategic Uses of Ambiguity in Cyberspace

    Directory of Open Access Journals (Sweden)

    Martin C. Libicki

    2011-12-01

    Full Text Available Strategic ambiguity has an honored place in the mores of statecraft. The studied unwillingness of states to say what they have done (or would do coupled with the lack of proof that they have done it (or would do it liberates other states. They can argue that something was done, but if their purposes so dictate, they can pretend that it was not done. The degree of doubt can vary: from thorough (no one is sure what has happened or would happen to nominal (no one is fooled. In either case, however, those who did it have provided a fig leaf, however translucent, that other states can adopt.

  13. Mobile Knowledge, Karma Points and Digital Peers: The Tacit Epistemology and Linguistic Representation of MOOCs

    Science.gov (United States)

    Portmess, Lisa

    2013-01-01

    Media representations of massive open online courses (MOOCs) such as those offered by Coursera, edX and Udacity reflect tension and ambiguity in their bold promise of democratized education and global knowledge sharing. An approach to MOOCs that emphasizes the tacit epistemology of such representations suggests a richer account of the ambiguities…

  14. On coherent-state representations of quantum mechanics: Wave mechanics in phase space

    DEFF Research Database (Denmark)

    Møller, Klaus Braagaard; Jørgensen, Thomas Godsk; Torres-Vega, Gabino

    1997-01-01

    In this article we argue that the state-vector phase-space representation recently proposed by Torres-Vega and co-workers [introduced in J. Chem. Phys. 98, 3103 (1993)] coincides with the totality of coherent-state representations for the Heisenberg-Weyl group. This fact leads to ambiguities when...

  15. Breaking the indexing ambiguity in serial crystallography.

    Science.gov (United States)

    Brehm, Wolfgang; Diederichs, Kay

    2014-01-01

    In serial crystallography, a very incomplete partial data set is obtained from each diffraction experiment (a `snapshot'). In some space groups, an indexing ambiguity exists which requires that the indexing mode of each snapshot needs to be established with respect to a reference data set. In the absence of such re-indexing information, crystallographers have thus far resorted to a straight merging of all snapshots, yielding a perfectly twinned data set of higher symmetry which is poorly suited for structure solution and refinement. Here, two algorithms have been designed for assembling complete data sets by clustering those snapshots that are indexed in the same way, and they have been tested using 15,445 snapshots from photosystem I [Chapman et al. (2011), Nature (London), 470, 73-77] and with noisy model data. The results of the clustering are unambiguous and enabled the construction of complete data sets in the correct space group P63 instead of (twinned) P6322 that researchers have been forced to use previously in such cases of indexing ambiguity. The algorithms thus extend the applicability and reach of serial crystallography.

  16. Management of ambiguities in magnetostratigraphic correlation

    Science.gov (United States)

    Lallier, Florent; Antoine, Christophe; Charreau, Julien; Caumon, Guillaume; Ruiu, Jeremy

    2013-06-01

    Magnetostratigraphy is a powerful tool to provide absolute dating of sediments enabling robust and detailed chronostratigraphic correlations. It is based on the correlation of a magnetic polarity column, observed and measured in a given sediment section, to a magnetic polarity reference scale where polarity changes are well dated via other independent methods. However, magnetostratigraphic correlations are loose as they are only constrained by binary magnetic chrons (i.e. normal or reversal) and their thickness, which are both defined from depth variations of the magnetic remanent directions. The thickness of a given magnetic polarity zone is a function of time and sediment accumulation rate, which may not be stationary, leading to ambiguities when performing the correlations. To address these ambiguities, a numerical method based on the Dynamic Time Warping algorithm is proposed. Magnetostratigraphic correlations are computed in order to minimise the local variation of the accumulation rate. The main advantage of the proposed method is to automatically provide a set of reasonably likely correlations. This set can then be scrutinised for further analysis and interpretation. However, the likelihood of a correlation should be handled carefully as it depends on the information content of the magnetostratigraphic section itself and remain ultimately valid by ancillary constraint. Nevertheless, the method gives consistent results on difficult synthetic cases that simulate abrupt variations of the sedimentation rate. Insights on true sections debated by previous authors are also given.

  17. The ambiguous nature of epigenetic responsibility.

    Science.gov (United States)

    Dupras, Charles; Ravitsky, Vardit

    2016-08-01

    Over the past decade, epigenetic studies have been providing further evidence of the molecular interplay between gene expression and its health outcomes on one hand, and the physical and social environments in which individuals are conceived, born and live on the other. As knowledge of epigenetic programming expands, a growing body of literature in social sciences and humanities is exploring the implications of this new field of study for contemporary societies. Epigenetics has been mobilised to support political claims, for instance, with regard to collective obligations to address socio-environmental determinants of health. The idea of a moral 'epigenetic responsibility' has been proposed, meaning that individuals and/or governments should be accountable for the epigenetic programming of children and/or citizens. However, these discussions have largely overlooked important biological nuances and ambiguities inherent in the field of epigenetics. In this paper, we argue that the identification and assignment of moral epigenetic responsibilities should reflect the rich diversity and complexity of epigenetic mechanisms, and not rely solely on a gross comparison between epigenetics and genetics. More specifically, we explore how further investigation of the ambiguous notions of epigenetic normality and epigenetic plasticity should play a role in shaping this emerging debate. PMID:27015741

  18. The clock ambiguity: Implications and new developments

    CERN Document Server

    Albrecht, Andreas

    2008-01-01

    We consider the ambiguity associated with the choice of clock in time reparameterization invariant theories. This arbitrariness undermines the goal of prescribing a fixed set of physical laws, since a change of time variable can completely alter the predictions of the theory. We review the main features of the clock ambiguity and our earlier work on its implications for the emergence of physical laws in a statistical manner. We also present a number of new results: We show that (contrary to suggestions in our earlier work) time independent Hamiltonians may quite generally be assumed for laws of physics that emerge in this picture. We also further explore the degree to which the observed Universe can be well approximated by a random Hamiltonian. We discuss the possibility of predicting the dimensionality of space, and also relate the 2nd derivative of the density of states to the heat capacity of the Universe. This new work adds to the viability of our proposal that strong predictions for physical laws may eme...

  19. GNSS carrier phase ambiguity resolution based on integrity restriction in ambiguity domain

    Science.gov (United States)

    Liu, Haiying; Chen, Zhiming; Ye, Weisong; Wang, Huinan

    2014-04-01

    Carrier phase ambiguity resolution of Global Navigation Satellite System (GNSS) is a key technology for high-precision navigation and positioning, and it is a challenge for applications which require both high accuracy and high integrity. This paper proposes efficient ambiguity resolution methods based on integrity restriction using Fixed Failure rate Ratio Test (FF-RT) and Doubly Non-central F-distribution Ratio Test (DNF-RT), and derives the related processing models and numerical algorithms compared with the traditional Ratio Test (RT) method. Firstly, the integer ambiguity resolution and validation procedures, especially the Least squares AMBiguity Decorrelation Adjustment (LAMBDA) estimation and RT validation are analyzed. Then the quality evaluation using success rate, the FF-RT method using Integer Aperture (IA) estimation and the NDF-RT method are proposed. Lastly, the simulation and analysis for LAMBDA using RT, FF-RT and DNF-RT methods are performed. Simulation results show that in case of unbiased scenario FF-RT and DNF-RT have similar performances, which are significantly better than RT. In case of biased scenario it is difficult for FF-RT to predict the biased success rate thus it should not be used for bias detection, while DNF-RT can detect biases in most cases except for the biases are approximate or equal to integer, which has the important benefit for early detection of potential threat to the position solution.

  20. Manipulating Representations.

    Science.gov (United States)

    Recchia-Luciani, Angelo N M

    2012-04-01

    The present paper proposes a definition for the complex polysemic concepts of consciousness and awareness (in humans as well as in other species), and puts forward the idea of a progressive ontological development of consciousness from a state of 'childhood' awareness, in order to explain that humans are not only able to manipulate objects, but also their mental representations. The paper builds on the idea of qualia intended as entities posing regular invariant requests to neural processes, trough the permanence of different properties. The concept of semantic differential introduces the properties of metaphorical qualia as an exclusively human ability. Furthermore this paper proposes a classification of qualia, according to the models-with different levels of abstraction-they are implied in, in a taxonomic perspective. This, in turn, becomes a source of categorization of divergent representations, sign systems, and forms of intentionality, relying always on biological criteria. New emerging image-of-the-world-devices are proposed, whose qualia are likely to be only accessible to humans: emotional qualia, where emotion accounts for the invariant and dominant property; and the qualic self where continuity, combined with the oneness of the self, accounts for the invariant and dominant property. The concept of congruence between different domains in a metaphor introduces the possibility of a general evaluation of truth and falsity of all kinds of metaphorical constructs, while the work of Matte Blanco enables us to classify conscious versus unconscious metaphors, both in individuals and in social organizations. PMID:22347988

  1. 一种基于双通道 LDA 模型的汉语词义%A Dual-LDA Method on Chinese Word Sense Representation and Induction

    Institute of Scientific and Technical Information of China (English)

    王少楠; 宗成庆

    2016-01-01

    Semantic memory is the foundation of human language understanding.Human brain needs to encode,retrieve and decode word meanings for language understanding.The semantic representation is the key step to develop natural language processing systems.Some studies have shown that the formation of concepts is affected by the interaction of human brain and the real world,and the concepts in human brain contain rich forms of information including vision, perception and language.Based on the distributional hypothesis which states that “similar words occur in similar contexts”,the concepts are represented as vectors by calculating the co-occurrence frequency of each word and its statistical features.In this way,word representation in computer can be seen as the semantic representation in human brain.This article mainly focuses on how to represent word senses and do word senses induction in natural language text.We first investigate the relation between computational models of word representation and semantic representation in human brain.Based on word similarity experiments,we have verified that word representations by statistical methods can capture the relationship of similarity between words in human brain.In the view of Chinese word sense disambiguation,this paper studies the methods to find the semantic features of ambiguities from context automatically.Bayesian probability model can learn word representations and do word sense induction together.Specifically,in order to do word sense induction,Bayesian probability model clusters words with the same topic.The words within the same topic can be seen as the representation of the topic.In the task of word sense induction,the topics are mapped to word senses in evaluation.Therefore,we use latent Dirichlet allocation model to learn word sense representation from large scale of corpus without annotation.On the basis of word sense representation,we do word sense induction on the testing data.In order to better capture the

  2. Representation of identities and the politics of representation in cognition

    Directory of Open Access Journals (Sweden)

    Kanavillil Rajagopalan

    2001-02-01

    Full Text Available

    In this paper, I make a plea for viewing representation as first and foremost a political matter. I argue that by so doing we may avoid the many of pitfalls of contemporary theories of cognition as they attempt to tackle the issue of representation. Most of these problems have to do with the fact that representation is treated exclusively as a mimetic or theatrical question. The fact of the matter is however that representation also has a political dimension. Indeed it has always had this political dimension which, counterintuitive though it may seem at first glimpse, manifests itself even in very the attempt to aestheticise the whole issue of representation (as in some versions of postmodernism or to deny its role altogether as a tertium quid between the external world and the cognising mind (as in contemporary neo-pragmatism. I also contend that, by recognising the political nature of representation, we also pave the way for endorsing the thesis that the mind is a social construct, thereby taking some steam out of the thesis of "mind-brain identity" (so-called "identity theory of mind".

  3. Azimuth Phase Coding for Range Ambiguity Suppression in SAR

    DEFF Research Database (Denmark)

    Dall, Jørgen; Kusk, Anders

    2004-01-01

    excels by actually eliminating the ambiguities rather than just defocusing them as most other techniques do. This makes the proposed technique applicable to distributed targets. The range ambiguity suppression permits the pulse repetition frequency (PRF) to exceed the upper limit otherwise defined...... by the antenna elevation dimension. The fundamental antenna area constraint still applies, but the PRF can be chosen with more freedom. In addition to ambiguity suppression, potential applications include nadir return elimination and signal-to-noise ratio improvement....

  4. Ambiguity, Ambivalence and Extravagance in The Hunger Games

    Directory of Open Access Journals (Sweden)

    Kelly Oliver

    2014-11-01

    Full Text Available I argue that Katniss Everdeen from The Hunger Games is an emblem of what Julia Kristeva calls the “extravagant girl” who wants to have it all and to be the best at everything. Katniss has an ambiguous gender identity, both masculine and feminine, paternal and maternal. And she has ambivalent desires. I conclude that this ambiguity and ambivalence open up new possibilities for girls and initiate an aesthetics of ambiguity.

  5. Lexical Ambiguity in Nouns: Frequency Dominance and Declensional Classes

    OpenAIRE

    Mancuso, Azzurra; Laudanna, Alessandro

    2014-01-01

    The existence of differences in lexical processing between ambiguous and unambiguous words is still controversial. Many factors seem to play a role in determining different ambiguity effects in word recognition, such as ambiguity type, experimental paradigm, frequency dominance, etc. The aim of this study is to investigate the role played by frequency dominance and declensional class in recognizing Italian homonymous nouns, namely, forms with multiple unrelated meaning...

  6. Elimination Method Study of Ambiguous Words in Chinese Automatic Indexing

    OpenAIRE

    Dan, Wang; Xiaorong, Yang; Jie, Zhang

    2013-01-01

    Faced with huge amounts of information to realize the accurate retrieval under the network environment, the first step is indexing words cannot appear ambiguity word. Because Chinese’s the basic unit is Chinese characters, Chinese characters form words, Word is divided into monosyllabic word and compound word, and there’s no space between Chinese keywords and there are a lot of ambiguous concept. Therefore a lot of ambiguity in the indexing process will be produced. The result detected inform...

  7. Differential diagnosis of ambiguous genitalia in Chines e patients

    Institute of Scientific and Technical Information of China (English)

    田秦杰; 葛秦生

    2002-01-01

    Objective: To study the etiology and differential diagnos is of ambiguous genitalia.Methods: One hundred and five cases of ambiguous genitalia with disorders of sexual differentiation were analyzed based on clinical characterist ics and basic research. Results: Ambiguous genitalia are closely related to the functio n of androgen. It could be classified into 3 groups: androgen excess, androgen d eficiency and failure of gonadal differentiation. Differential diagnosis depends on clinical manifestations, chromosome examination, serum hormone determination s, final gonadal pathology, receptor study etc.Conclusion: Ambiguous genitalia are related to abnormal androgen ic effect and early correct etiological diagnosis is the key to its management.

  8. Ambiguous Loss Experienced by Transnational Mexican Immigrant Families.

    Science.gov (United States)

    Solheim, Catherine; Zaid, Samantha; Ballard, Jaime

    2016-06-01

    In this study, an ambiguous loss framework as described by Boss (1999, Ambiguous loss: Learning to live with unresolved grief, First Harvard University Press, Cambridge, MA) was used to examine and understand the family experiences of Mexican immigrant agricultural workers in Minnesota. Transcripts from interviews with 17 workers in Minnesota and 17 family members in Mexico were analyzed using qualitative methodology to identify experiences of ambiguous loss in the participants' narratives. Key dimensions of ambiguous loss identified in the transcripts include: psychological family, feelings of chronic/recurring loss, finding support, and meaning making. In the category of psychological family, participants in both Mexico and the United States mourned the physical absence of their family members and experienced ambiguity regarding family responsibilities, but worked to maintain their psychological roles within the family. In the category of chronic/recurring loss, participants in both countries experienced chronic worry from not knowing if family members were safe, ambiguity regarding when the immigrant would return, and chronic stressors that compounded these feelings of loss. Participants in both countries coped with both real and ambiguous losses by accessing family support and by using ambiguous communication to minimize worry. Participants in Mexico also accessed work and community-based support. Participants in both countries made meaning of the ambiguous loss by identifying ways their lives were improved and goals were met as a result of the immigration for agricultural work in Minnesota. PMID:25619113

  9. Dealing with the Ambiguities of Science Inquiry

    Science.gov (United States)

    Tan, Yuen Sze Michelle; Caleon, Imelda Santos

    2016-03-01

    The current vision of science education in myriad educational contexts encourages students to learn through the process of science inquiry. Science inquiry has been used to promote conceptual learning and engage learners in an active process of meaning-making and investigation to understand the world around them. The science inquiry process typically involves asking questions and defining problems; constructing explanations and designing solutions; planning and carrying out investigations; analyzing and interpreting data; and engaging in argument from evidence. Despite the importance and provision of new directions and standards about science inquiry, ambiguities in conceptualizations of inquiry still exist. These conceptualizations may serve as barriers to students learning science. In this article, we detail three main concerns related to teachers' conceptualization of science inquiry in the context of a Singapore classroom—concerns that may be similarly faced by teachers elsewhere.

  10. Fast Computation of Cross-Ambiguity Function

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A novel method based on zoom fast Fourier transform(FFT) is proposed for minimizing the burden processing of cross-ambiguity functions without affecting performance. The low-pass anti-aliasing filter in zoom FFT is realized by using the multistage filtering technique and the weighting processing is employed in the first stage filter to get rid of the redundancy of the computation. In practical systems, the input data is divided into overlapped data frames to avoid loss of detection ability which results in the rapid increase of computational complexity. A segment technique is also proposed in which CAF calculation of overlapped data frames is viewed as slide window FFT to decrease the computational complexity. The experimental results show that compared to the conventional methods, the proposed method can lower computational complexity and is consistent with the real time implementation in existing high-speed digital processors.

  11. Length Matters: Informational Load in Ambiguity Resolution

    Directory of Open Access Journals (Sweden)

    Barbara Hemforth

    2013-07-01

    Full Text Available In this paper, we will compare prosodic and pragmatic approaches to the role of constituent length in attachment ambiguities. Lengthening a constituent affects its informativity: longer constituents are usually less predictable (Levy & Florian, 2007 and demand a higher processing load than shorter ones (Almor, 1999. Following neo-Gricean accounts (Levinson, 1987 and 1991, increased informational load needs to be justified. This justification is achieved more easily when the long constituent conveys new information and when it relates to central elements of the utterance. Informational load is, however, not a simple question of length in numbers of characters or syllables but more likely a question of amount of information. In three off-line experiments using a cloze task, we will compare the effect of lengthening ambiguous prepositional phrases as in [1a/b/c] either by lengthening a city name or by adding information about the city. We will show that only lengthening by adding information increases attachment to a more central element of the utterance. These results will be discussed based on prosodic and pragmatic factors explaining the role of constituent length for attachment ambiguities.[1] Peter met the doctor of the lawyer from a. Apt. / b. Aix-en-Provence / c. the beautiful city of Apt.Dans cet article, nous comparons une approche prosodique avec une approche pragmatique pour rendre compte des effets de la longueur des constituants dans les ambigüités d’attachement. Augmenter la longueur d’un constituant a des conséquences sur l’information qu’il véhicule : plus un constituant est long et moins il est prédictible (Levy et Florian, 2007 et plus son coût de traitement augmente (Almor, 1999. Suivant les principes néo-gricéens (Levinson, 1987 et 1991, augmenter le poids informationnel doit être justifié. Cette justification est plus facilement satisfaite lorsqu’un constituant long véhicule une information

  12. [Ambiguity role of neutrophils in oncogenesis].

    Science.gov (United States)

    Mal'tseva, V N; Safronova, V G

    2009-01-01

    The review is focused on the participation of polymorphonuclear granulocytes (neutrophils) in development and spreading of a tumor. We consider both the well known functions of neutrophils (degranulation, production of reactive oxygen species (ROS)) and the recently shown one (presentation of an antigene). The special attention is focused on the ambiguity of the neutrophil role in oncogenesis. The dominant view is that neutrophils display exclusively antitumor properties. The update information testifies about protumoral activity of neutrophils: they migrate to a tumor and promote angiogenesis and metastasis at late stages of the tumor. It is interesting that certain components of neutrophil cytotoxic arsenal (ROS, cytokines, specific enzymes) participate both in antitumoral defenses of an organism and protumoral activity. PMID:19637749

  13. Decreasing Ambiguity of the Safety Culture Concept

    International Nuclear Information System (INIS)

    The status of the concept of ''safety culture'' is reviewed. It has not sufficiently taken root. One cause for this is the abstract nature of the concept. Organizations must become aware of the necessity of improving safety and have sufficient power to promote this. The culture of safety must be instilled in each employee, so that each of them will feel responsible for identifying weak points in plant safety. The authors devised a tool for a self-assessment of the safety culture. The tool will bring to light information divides, communication gaps, etc. Recognizing the vulnerabilities of the organization by themselves and discussing these weak points among them is the first step to decrease the ambiguity of the safety culture. The next step is to make these gaps known along with agreed-upon countermeasures. The concept of safety culture will be greatly clarified in this way and lead to safer nuclear power plants

  14. How ambiguous is the local kinetic energy?

    Science.gov (United States)

    Anderson, James S M; Ayers, Paul W; Hernandez, Juan I Rodriguez

    2010-08-26

    The local kinetic energy and the closely related local electronic stress tensor are commonly used to elucidate chemical bonding patterns, especially for covalent bonds. We use three different approaches-transformation properties of the stress tensor, quasiprobability distributions, and the virial theorem from density-functional theory-to clarify the inherent ambiguity in these quantities, discussing the implications for analyses based on the local kinetic energy and stress tensor. An expansive-but not universal-family of local kinetic energy forms that includes the most common choices and is suitable for both chemical-bonding and atoms-in-molecule analysis is derived. A family of local electronic stress tensors is also derived. Several local kinetic energy functions that are mathematically justified, but unlikely to be conceptually useful, are derived. The implications of these forms for atoms-in-molecule analysis are discussed. PMID:20586467

  15. How ambiguous is the local kinetic energy?

    Science.gov (United States)

    Anderson, James S M; Ayers, Paul W; Hernandez, Juan I Rodriguez

    2010-08-26

    The local kinetic energy and the closely related local electronic stress tensor are commonly used to elucidate chemical bonding patterns, especially for covalent bonds. We use three different approaches-transformation properties of the stress tensor, quasiprobability distributions, and the virial theorem from density-functional theory-to clarify the inherent ambiguity in these quantities, discussing the implications for analyses based on the local kinetic energy and stress tensor. An expansive-but not universal-family of local kinetic energy forms that includes the most common choices and is suitable for both chemical-bonding and atoms-in-molecule analysis is derived. A family of local electronic stress tensors is also derived. Several local kinetic energy functions that are mathematically justified, but unlikely to be conceptually useful, are derived. The implications of these forms for atoms-in-molecule analysis are discussed.

  16. Risk, ambiguity and quantum decision theory

    CERN Document Server

    Franco, Riccardo

    2007-01-01

    In the present article we use the quantum formalism to describe the effects of risk and ambiguity in decision theory. The main idea is that the probabilities in the classic theory of expected utility are estimated probabilities, and thus do not follow the classic laws of probability theory. In particular, we show that it is possible to use consistently the classic expected utility formula, where the probability associated to the events are computed with the equation of quantum interference. Thus we show that the correct utility of a lottery can be simply computed by adding to the classic expected utility a new corrective term, the uncertainty utility, directly connected with the quantum interference term.

  17. Resolving deconvolution ambiguity in gene alternative splicing

    Directory of Open Access Journals (Sweden)

    Hubbell Earl

    2009-08-01

    Full Text Available Abstract Background For many gene structures it is impossible to resolve intensity data uniquely to establish abundances of splice variants. This was empirically noted by Wang et al. in which it was called a "degeneracy problem". The ambiguity results from an ill-posed problem where additional information is needed in order to obtain an unique answer in splice variant deconvolution. Results In this paper, we analyze the situations under which the problem occurs and perform a rigorous mathematical study which gives necessary and sufficient conditions on how many and what type of constraints are needed to resolve all ambiguity. This analysis is generally applicable to matrix models of splice variants. We explore the proposal that probe sequence information may provide sufficient additional constraints to resolve real-world instances. However, probe behavior cannot be predicted with sufficient accuracy by any existing probe sequence model, and so we present a Bayesian framework for estimating variant abundances by incorporating the prediction uncertainty from the micro-model of probe responsiveness into the macro-model of probe intensities. Conclusion The matrix analysis of constraints provides a tool for detecting real-world instances in which additional constraints may be necessary to resolve splice variants. While purely mathematical constraints can be stated without error, real-world constraints may themselves be poorly resolved. Our Bayesian framework provides a generic solution to the problem of uniquely estimating transcript abundances given additional constraints that themselves may be uncertain, such as regression fit to probe sequence models. We demonstrate the efficacy of it by extensive simulations as well as various biological data.

  18. Decoding covert shifts of attention induced by ambiguous visuospatial cues

    Directory of Open Access Journals (Sweden)

    Romain eTrachel

    2015-06-01

    Full Text Available Simple and unambiguous visual cues (e.g. an arrow can be used to trigger covert shifts of visual attention away from the center of gaze. The processing of visual stimuli is enhanced at the attended location. Covert shifts of attention modulate the power of cerebral oscillations in the alpha band over parietal and occipital regions. These modulations are sufficiently robust to be decoded on a single trial basis from electro-encephalography (EEG signals. It is often assumed that covert attention shifts are under voluntary control, and also occur in more natural and complex environments, but there is no direct evidence to support this assumption. We address this important issue by using random-dot stimuli to cue one of two opposite locations, where a visual target is presented. We contrast two conditions in which the random-dot motion is either predictive of the target location or contains ambiguous information. Behavioral results show attention shifts in anticipation of the visual target, in both conditions. In addition, these attention shifts involve similar neural sources, and the EEG can be decoded on a single trial basis. These results shed a new light on the behavioral and neural correlates of visuospatial attention, with implications for Brain-Computer Interfaces (BCI based on covert attention shifts.

  19. Neural Imaginaries and Clinical Epistemology: Rhetorically Mapping the Adolescent Brain in the Clinical Encounter

    Science.gov (United States)

    Buchbinder, Mara

    2014-01-01

    The social work of brain images has taken center stage in recent theorizing of the intersections between neuroscience and society. However, neuroimaging is only one of the discursive modes through which public representations of neurobiology travel. This article adopts an expanded view toward the social implications of neuroscientific thinking to examine how neural imaginaries are constructed in the absence of visual evidence. Drawing on ethnographic fieldwork conducted over 18 months (2008–2009) in a United States multidisciplinary pediatric pain clinic, I examine the pragmatic clinical work undertaken to represent ambiguous symptoms in neurobiological form. Focusing on one physician, I illustrate how, by rhetorically mapping the brain as a therapeutic tool, she engaged in a distinctive form of representation that I call neural imagining. In shifting my focus away from the purely material dimensions of brain images, I juxtapose the cultural work of brain scanning technologies with clinical neural imaginaries in which the teenage brain becomes a space of possibility, not to map things as they are, but rather, things as we hope they might be. These neural imaginaries rely upon a distinctive clinical epistemology that privileges the creative work of the imagination over visualization technologies in revealing the truths of the body. By creating a therapeutic space for adolescents to exercise their imaginative faculties and a discursive template for doing so, neural imagining relocates adolescents’ agency with respect to epistemologies of bodily knowledge and the role of visualization practices therein. In doing so, it provides a more hopeful alternative to the dominant popular and scientific representations of the teenage brain that view it primarily through the lens of pathology. PMID:24780561

  20. Neural imaginaries and clinical epistemology: Rhetorically mapping the adolescent brain in the clinical encounter.

    Science.gov (United States)

    Buchbinder, Mara

    2015-10-01

    The social work of brain images has taken center stage in recent theorizing of the intersections between neuroscience and society. However, neuroimaging is only one of the discursive modes through which public representations of neurobiology travel. This article adopts an expanded view toward the social implications of neuroscientific thinking to examine how neural imaginaries are constructed in the absence of visual evidence. Drawing on ethnographic fieldwork conducted over 18 months (2008-2009) in a United States multidisciplinary pediatric pain clinic, I examine the pragmatic clinical work undertaken to represent ambiguous symptoms in neurobiological form. Focusing on one physician, I illustrate how, by rhetorically mapping the brain as a therapeutic tool, she engaged in a distinctive form of representation that I call neural imagining. In shifting my focus away from the purely material dimensions of brain images, I juxtapose the cultural work of brain scanning technologies with clinical neural imaginaries in which the teenage brain becomes a space of possibility, not to map things as they are, but rather, things as we hope they might be. These neural imaginaries rely upon a distinctive clinical epistemology that privileges the creative work of the imagination over visualization technologies in revealing the truths of the body. By creating a therapeutic space for adolescents to exercise their imaginative faculties and a discursive template for doing so, neural imagining relocates adolescents' agency with respect to epistemologies of bodily knowledge and the role of visualization practices therein. In doing so, it provides a more hopeful alternative to the dominant popular and scientific representations of the teenage brain that view it primarily through the lens of pathology.

  1. Top-Down Influence in Young Children's Linguistic Ambiguity Resolution

    Science.gov (United States)

    Rabagliati, Hugh; Pylkkanen, Liina; Marcus, Gary F.

    2013-01-01

    Language is rife with ambiguity. Do children and adults meet this challenge in similar ways? Recent work suggests that while adults resolve syntactic ambiguities by integrating a variety of cues, children are less sensitive to top-down evidence. We test whether this top-down insensitivity is specific to syntax or a general feature of children's…

  2. Ambiguity Tolerance and Perceptual Learning Styles of Chinese EFL Learners

    Science.gov (United States)

    Li, Haishan; He, Qingshun

    2016-01-01

    Ambiguity tolerance and perceptual learning styles are the two influential elements showing individual differences in EFL learning. This research is intended to explore the relationship between Chinese EFL learners' ambiguity tolerance and their preferred perceptual learning styles. The findings include (1) the learners are sensitive to English…

  3. DIRECTION AMBIGUITY RESOLUTION FROM SAR IMAGERY: A NEW APPROACH

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Ambiguity problem is inherent in synthetic aperture radar (SAR)images of ocean waves. A new method is developed based on the propagation theory of gravity waves to remove this kind of ambiguity from a single frame of real image. The results from a case study presented in this paper show good agreement to in-phase wave data.

  4. Kindergarten Children Can Be Taught to Detect Lexical Ambiguities

    Science.gov (United States)

    Kamowski-Shakibai, Margaret T.; Cairns, Helen Smith

    2016-01-01

    This study investigates the development of metalinguistic skills, particularly ambiguity detection, and whether training accelerates this development for prereaders in kindergarten (5;5-6;6). It is the first to compare homophone detection with lexically ambiguous sentence detection in which the same homophones appear. The experimental group…

  5. Ambiguity and the ‘mental eye’ in pictorial relief

    NARCIS (Netherlands)

    Koenderink, J.J.; Doorn, A.J. van; Kappers, A.M.L.

    2001-01-01

    Photographs of scenes do not determine scenes in the sense that infinitely many different scenes could have given rise to any given photograph. In psychophysical experiments, observers have (at least partially) to resolve these ambiguities. The ambiguities also allow them to vary their response with

  6. An Analysis on Positive Impacts of Communication Ambiguity

    Institute of Scientific and Technical Information of China (English)

    Liu Siyu

    2015-01-01

    This essay briefly introduces the factors of communication ambiguity and makes an analysis on them. Accordingly,several suggestions are given to help people to deal with the difficulties it brings to their life.In terms of the influence of communication ambiguity,the essay mainly focuses on the positive side.

  7. An Analysis on Positive Impacts of Communication Ambiguity

    Institute of Scientific and Technical Information of China (English)

    Liu; Siyu

    2015-01-01

    This essay briefly introduces the factors of communication ambiguity and makes an analysis on them.Accordingly,several suggestions are given to help people to deal with the difficulties it brings to their life.In terms of the influence of communication ambiguity,the essay mainly focuses on the positive side.

  8. GLONASS ionosphere-free ambiguity resolution for precise point positioning

    Science.gov (United States)

    Banville, Simon

    2016-05-01

    Current GLONASS satellites transmit signals based on the frequency division multiple access (FDMA) technology. Due to equipment delays occurring within GNSS receivers, GLONASS carrier phase and code observations are contaminated by inter-frequency biases. As a consequence, GLONASS ambiguity parameters in long-baseline processing are typically estimated as float values. In this paper, a strategy is investigated which benefits from the frequency spacing of GLONASS frequencies on the L1 and L2 bands, allowing for an ionosphere-free ambiguity with a wavelength of approximately 5 cm to be defined; therefore, avoiding the problematic wide-lane ambiguity resolution. Based on 12 independent baselines with a mean inter-station distance of about 850 km over a 1-week period, it is demonstrated that close to 95 % of the estimated double-differenced ionosphere-free ambiguities are within 0.15 cycles of an integer, thereby suggesting that long-baseline ambiguity resolution can be achieved for GLONASS. Applying between-station ambiguity constraints in precise point positioning (PPP) solutions was found to improve longitudinal repeatability in static mode by more than 20 % for sessions between 2 and 6 h in duration. In kinematic mode, only limited improvements were made to the initial convergence period since the short wavelength of GLONASS ionosphere-free ambiguities requires the solution to be nearly converged before successful ambiguity resolution can be achieved.

  9. Examining English-German Translation Ambiguity Using Primed Translation Recognition

    Science.gov (United States)

    Eddington, Chelsea M.; Tokowicz, Natasha

    2013-01-01

    Many words have more than one translation across languages. Such "translation-ambiguous" words are translated more slowly and less accurately than their unambiguous counterparts. We examine the extent to which word context and translation dominance influence the processing of translation-ambiguous words. We further examine how these factors…

  10. Children's Understanding of Ambiguous Idioms and Conversational Perspective-Taking

    Science.gov (United States)

    Le Sourn-Bissaoui, Sandrine; Caillies, Stephanie; Bernard, Stephane; Deleau, Michel; Brule, Lauriane

    2012-01-01

    The aim of this study was to test the hypothesis that conversational perspective-taking is a determinant of unfamiliar ambiguous idiom comprehension. We investigated two types of ambiguous idiom, decomposable and nondecomposable expressions, which differ in the degree to which the literal meanings of the individual words contribute to the overall…

  11. Lexical Ambiguity Resolution: Word Processing, Recognition and Context Effect

    Science.gov (United States)

    Kilickaya, Ferit

    2007-01-01

    In the paper the lexical ambiguity resolution is presented. The paper is specifically focused on the processing of words, models of word recognition, context effect, trying to find an answer to how the reader-listener determines the contextually appropriate meaning of a word. Ambiguity resolution is analyzed and explored in two perspectives: the…

  12. Process ambiguities in Sino-Danish Business Negotiations

    DEFF Research Database (Denmark)

    Kumar, Rajesh; Worm, Verner

    2004-01-01

    . These ambiguities stem from differences in negotiation scripts across Danish and Chinese cultures. The essential argument being advanced here is that it is the effective and/or the ineffective management of process ambiguities that shapes the evolution of the negotiating dynamic between the Danish and the Chinese...

  13. Absence of the Gribov ambiguity in a quadratic gauge

    Energy Technology Data Exchange (ETDEWEB)

    Raval, Haresh [Indian Institute of Technology, Bombay, Department of Physics, Mumbai (India)

    2016-05-15

    The Gribov ambiguity exists in various gauges. Algebraic gauges are likely to be ambiguity free. However, algebraic gauges are not Lorentz invariant, which is their fundamental flaw. In addition, they are not generally compatible with the boundary conditions on the gauge fields, which are needed to compactify the space i.e., the ambiguity continues to exist on a compact manifold. Here we discuss a quadratic gauge fixing, which is Lorentz invariant. We consider an example of a spherically symmetric gauge field configuration in which we prove that this Lorentz invariant gauge removes the ambiguity on a compact manifold S{sup 3}, when a proper boundary condition on the gauge configuration is taken into account. Thus, we provide one example where the ambiguity is absent on a compact manifold in the algebraic gauge. We also show that the BRST invariance is preserved in this gauge. (orig.)

  14. Actively learning object names across ambiguous situations.

    Science.gov (United States)

    Kachergis, George; Yu, Chen; Shiffrin, Richard M

    2013-01-01

    Previous research shows that people can use the co-occurrence of words and objects in ambiguous situations (i.e., containing multiple words and objects) to learn word meanings during a brief passive training period (Yu & Smith, 2007). However, learners in the world are not completely passive but can affect how their environment is structured by moving their heads, eyes, and even objects. These actions can indicate attention to a language teacher, who may then be more likely to name the attended objects. Using a novel active learning paradigm in which learners choose which four objects they would like to see named on each successive trial, this study asks whether active learning is superior to passive learning in a cross-situational word learning context. Finding that learners perform better in active learning, we investigate the strategies and discover that most learners use immediate repetition to disambiguate pairings. Unexpectedly, we find that learners who repeat only one pair per trial--an easy way to infer this pair-perform worse than those who repeat multiple pairs per trial. Using a working memory extension to an associative model of word learning with uncertainty and familiarity biases, we investigate individual differences that correlate with these assorted strategies. PMID:23335580

  15. Ambiguous genitalia: a clinical and chromosomal study

    Directory of Open Access Journals (Sweden)

    V. Anantha Kumari

    2015-12-01

    Methods: The study is undertaken with forty cases with ages ranging from new borne to 20 yrs. Out of these 40 cases eight cases are below one year. In these cases physical examination is correlated with ultrasonography and chromosomal analysis. Results: In chromosomal analysis three persons out of forty cases were mosaics with 45, XO/46, twenty one cases who showed the chromosomal pattern as 46, XY mostly showed with no mullarian reminents. On examination palpable gonads were found in labio-scrotal sacs in seventeen cases. One of these cases was reared as girl found cytogenetically as 46, XY with the ultrasonographic impression as small uterus with no ovaries. Nineteen cases who with ambiguous genitalia showed the chromosomal pattern as 46, XX one out of these cases showed enlargement of the breast, and on examination of external genitalia found enlarged clitoris with labiamajora and minora. The child was brought up as male. Genitogram showed the absence of uterus. Conclusions: Chromosomal studies with ultrasonography can help in rearing a child male or female in young generation by surgical and Hormonal therapy. This prevents many problems in later life. This fact should be advertised openly in the public so that illiterate people should be alert. [Int J Res Med Sci 2015; 3(12.000: 3743-3748

  16. Conceptual Representation Changes in Indonesian-English Bilinguals.

    Science.gov (United States)

    Hartanto, Andree; Suárez, Lidia

    2016-10-01

    This study investigated conceptual representations changes in bilinguals. Participants were Indonesian-English bilinguals (dominant in Indonesian, with different levels of English proficiency) and a control group composed of English-dominant bilinguals. All completed a gender decision task, in which participants decided whether English words referred to a male or female person or animal. In order to explore conceptual representations, we divided the words into gender-specific and gender-ambiguous words. Gender-specific words were words in which conceptual representations contained gender as a defining feature, in both English and Indonesian (e.g., uncle). In contrast, gender-ambiguous words were words in which gender was a defining feature in English but not a necessary feature in Indonesian (e.g., nephew and niece are both subsumed under the same word, keponakan, in Indonesian). The experiment was conducted exclusively in English. Indonesian-English bilinguals responded faster to gender-specific words than gender-ambiguous words, but the difference was smaller for the most proficient bilinguals. As expected, English-dominant speakers' response latencies were similar across these two types of words. The results suggest that English concepts are dynamic and that proficiency leads to native-like conceptual representations.

  17. X-Linked Lissencephaly with Absent Corpus Callosum and Ambiguous Genitalia: A Case Report

    Directory of Open Access Journals (Sweden)

    Alireza Jashni Motlagh

    2016-03-01

    Case presentation: The patient was a one-day-old term neonate admitted to our neonatal intensive care unit due to refractory seizure. He was the second child of the family, born to non-consanguineous and healthy parents. His midface was slightly hypoplastic with long and smooth philtrum; the neonate had ambiguous genitalia, as well. Hormonal investigation demonstrated elevated serum 17OH-progesterone, dehydroepiandrosterone sulfate, and testosterone levels. Chromosomal analysis showed a normal male karyotype (46, XY. Brain computed tomography scan showed a typical pattern of lissencephaly with a posterior-to-anterior gradient of severity consisting of frontal pachygyria, posterior agyria, and absence of corpus collosum

  18. Factorizations and Physical Representations

    OpenAIRE

    Revzen, M.; F. C. Khanna(Edmonton, Canada); Mann, A.; Zak, J.

    2005-01-01

    A Hilbert space in M dimensions is shown explicitly to accommodate representations that reflect the prime numbers decomposition of M. Representations that exhibit the factorization of M into two relatively prime numbers: the kq representation (J. Zak, Phys. Today, {\\bf 23} (2), 51 (1970)), and related representations termed $q_{1}q_{2}$ representations (together with their conjugates) are analysed, as well as a representation that exhibits the complete factorization of M. In this latter repre...

  19. Memory cueing during sleep modifies the interpretation of ambiguous scenes in adolescents and adults

    Directory of Open Access Journals (Sweden)

    Sabine Groch

    2016-02-01

    Full Text Available The individual tendency to interpret ambiguous situations negatively is associated with mental disorders. Interpretation biases are already evident during adolescence and due to the greater plasticity of the developing brain it may be easier to change biases during this time. We investigated in healthy adolescents and adults whether stabilizing memories of positive or negative scenes modulates the later interpretation of similar scenes. In the evening, participants learnt associations between ambiguous pictures and words that disambiguate the valence of the pictures in a positive or negative direction. Half of the words were acoustically presented (i.e. cued during post-learning sleep which is known to benefit memory consolidation by inducing reactivation of learned information. Cued compared to un-cued stimuli were remembered better the next morning. Importantly, cueing positively disambiguated pictures resulted in more positive interpretations whereas cueing negatively disambiguated pictures led to less positive interpretations of new ambiguous pictures with similar contents the next morning. These effects were not modulated by participants’ age indicating that memory cueing was as efficient in adolescents as in adults. Our findings suggest that memory cueing during sleep can modify interpretation biases by benefitting memory stabilization and generalization. Implications for clinical settings are discussed.

  20. Memory cueing during sleep modifies the interpretation of ambiguous scenes in adolescents and adults.

    Science.gov (United States)

    Groch, Sabine; McMakin, Dana; Guggenbühl, Patrick; Rasch, Björn; Huber, Reto; Wilhelm, Ines

    2016-02-01

    The individual tendency to interpret ambiguous situations negatively is associated with mental disorders. Interpretation biases are already evident during adolescence and due to the greater plasticity of the developing brain it may be easier to change biases during this time. We investigated in healthy adolescents and adults whether stabilizing memories of positive or negative scenes modulates the later interpretation of similar scenes. In the evening, participants learnt associations between ambiguous pictures and words that disambiguate the valence of the pictures in a positive or negative direction. Half of the words were acoustically presented (i.e. cued) during post-learning sleep which is known to benefit memory consolidation by inducing reactivation of learned information. Cued compared to un-cued stimuli were remembered better the next morning. Importantly, cueing positively disambiguated pictures resulted in more positive interpretations whereas cueing negatively disambiguated pictures led to less positive interpretations of new ambiguous pictures with similar contents the next morning. These effects were not modulated by participants' age indicating that memory cueing was as efficient in adolescents as in adults. Our findings suggest that memory cueing during sleep can modify interpretation biases by benefitting memory stabilization and generalization. Implications for clinical settings are discussed. PMID:26588358

  1. Consistent representations of and conversions between 3D rotations

    Science.gov (United States)

    Rowenhorst, D.; Rollett, A. D.; Rohrer, G. S.; Groeber, M.; Jackson, M.; Konijnenberg, P. J.; De Graef, M.

    2015-12-01

    In materials science the orientation of a crystal lattice is described by means of a rotation relative to an external reference frame. A number of rotation representations are in use, including Euler angles, rotation matrices, unit quaternions, Rodrigues-Frank vectors and homochoric vectors. Each representation has distinct advantages and disadvantages with respect to the ease of use for calculations and data visualization. It is therefore convenient to be able to easily convert from one representation to another. However, historically, each representation has been implemented using a set of often tacit conventions; separate research groups would implement different sets of conventions, thereby making the comparison of methods and results difficult and confusing. This tutorial article aims to resolve these ambiguities and provide a consistent set of conventions and conversions between common rotational representations, complete with worked examples and a discussion of the trade-offs necessary to resolve all ambiguities. Additionally, an open source Fortran-90 library of conversion routines for the different representations is made available to the community.

  2. Practice makes perfect: Training the interpretation of emotional ambiguity.

    Science.gov (United States)

    Clifton, Jessica L; Hedley, Sophie; Mountier, Emily; Tiszai, Boglarka; Grimshaw, Gina M

    2016-01-01

    The interpretation of emotionally ambiguous words, sentences, or scenarios can be altered through training procedures that are collectively called cognitive bias modification for interpretation (CBM-I). In three experiments, we systematically manipulated the nature of the training in order to discriminate between emotional priming and ambiguity resolution accounts of training effects. In Experiment 1 participants completed word fragments that were consistently related to either a negative or benign interpretation of an ambiguous sentence. In a subsequent semantic priming task they demonstrated an interpretation bias, in that they were faster to identify relatedness of targets that were associated with the training-congruent meaning of an emotionally ambiguous homograph. We then manipulated the training sentences to show that interpretation bias was eliminated when participants simply completed valenced word fragments following unrelated sentences (Experiment 2), or completed fragments that were related to emotional but unambiguous sentences (Experiment 3). Only when participants were required to actively resolve emotionally ambiguous sentences during training did changes in interpretation emerge at test. Findings suggest that CBM-I achieves its effects by altering a production rule that aids the selection of meaning from emotionally ambiguous alternatives, in line with an ambiguity resolution account. PMID:25807872

  3. Statistical resolution of ambiguous HLA typing data.

    Directory of Open Access Journals (Sweden)

    Jennifer Listgarten

    2008-02-01

    Full Text Available High-resolution HLA typing plays a central role in many areas of immunology, such as in identifying immunogenetic risk factors for disease, in studying how the genomes of pathogens evolve in response to immune selection pressures, and also in vaccine design, where identification of HLA-restricted epitopes may be used to guide the selection of vaccine immunogens. Perhaps one of the most immediate applications is in direct medical decisions concerning the matching of stem cell transplant donors to unrelated recipients. However, high-resolution HLA typing is frequently unavailable due to its high cost or the inability to re-type historical data. In this paper, we introduce and evaluate a method for statistical, in silico refinement of ambiguous and/or low-resolution HLA data. Our method, which requires an independent, high-resolution training data set drawn from the same population as the data to be refined, uses linkage disequilibrium in HLA haplotypes as well as four-digit allele frequency data to probabilistically refine HLA typings. Central to our approach is the use of haplotype inference. We introduce new methodology to this area, improving upon the Expectation-Maximization (EM-based approaches currently used within the HLA community. Our improvements are achieved by using a parsimonious parameterization for haplotype distributions and by smoothing the maximum likelihood (ML solution. These improvements make it possible to scale the refinement to a larger number of alleles and loci in a more computationally efficient and stable manner. We also show how to augment our method in order to incorporate ethnicity information (as HLA allele distributions vary widely according to race/ethnicity as well as geographic area, and demonstrate the potential utility of this experimentally. A tool based on our approach is freely available for research purposes at http://microsoft.com/science.

  4. From Positivity to Negativity Bias: Ambiguity Affects the Neurophysiological Signatures of Feedback Processing.

    Science.gov (United States)

    Gibbons, Henning; Schnuerch, Robert; Stahl, Jutta

    2016-04-01

    Previous studies on the neurophysiological underpinnings of feedback processing almost exclusively used low-ambiguity feedback, which does not fully address the diversity of situations in everyday life. We therefore used a pseudo trial-and-error learning task to investigate ERPs of low- versus high-ambiguity feedback. Twenty-eight participants tried to deduce the rule governing visual feedback to their button presses in response to visual stimuli. In the blocked condition, the same two feedback words were presented across several consecutive trials, whereas in the random condition feedback was randomly drawn on each trial from sets of five positive and five negative words. The feedback-related negativity (FRN-D), a frontocentral ERP difference between negative and positive feedback, was significantly larger in the blocked condition, whereas the centroparietal late positive complex indicating controlled attention was enhanced for negative feedback irrespective of condition. Moreover, FRN-D in the blocked condition was due to increased reward positivity (Rew-P) for positive feedback, rather than increased (raw) FRN for negative feedback. Our findings strongly support recent lines of evidence that the FRN-D, one of the most widely studied signatures of reinforcement learning in the human brain, critically depends on feedback discriminability and is primarily driven by the Rew-P. A novel finding concerned larger frontocentral P2 for negative feedback in the random but not the blocked condition. Although Rew-P points to a positivity bias in feedback processing under conditions of low feedback ambiguity, P2 suggests a specific adaptation of information processing in case of highly ambiguous feedback, involving an early negativity bias. Generalizability of the P2 findings was demonstrated in a second experiment using explicit valence categorization of highly emotional positive and negative adjectives. PMID:26765948

  5. Quantum Cognition based on an Ambiguous Representation Derived from a Rough Set Approximation

    OpenAIRE

    GUNJI, Yukio-Pegio; Sonoda, Kohei; Basios, Vasileios

    2014-01-01

    Over the last years, in a series papers by Arrechi and others, a model for the cognitive processes involved in decision making has been proposed and investigated. The key element of this model is the expression of apprehension and judgement, basic cognitive process of decision making, as an inverse Bayes inference classifying the information content of neuron spike trains. For successive plural stimuli, it has been shown that this inference, equipped with basic non-algorithmic jumps, is affec...

  6. A method to reduce ambiguities of qualitative reasoning for conceptual design applications

    NARCIS (Netherlands)

    D'Amelio, V.; Chmarra, M.K.; Tomiyama, T.

    2013-01-01

    Qualitative reasoning can generate ambiguous behaviors due to the lack of quantitative information. Despite many different research results focusing on ambiguities reduction, fundamentally it is impossible to totally remove ambiguities with only qualitative methods and to guarantee the consistency o

  7. Robust portfolio choice with ambiguity and learning about return predictability

    DEFF Research Database (Denmark)

    Larsen, Linda Sandris; Branger, Nicole; Munk, Claus

    2013-01-01

    We analyze the optimal stock-bond portfolio under both learning and ambiguity aversion. Stock returns are predictable by an observable and an unobservable predictor, and the investor has to learn about the latter. Furthermore, the investor is ambiguity-averse and has a preference for investment...... strategies that are robust to model misspecifications. We derive a closed-form solution for the optimal robust investment strategy. We find that both learning and ambiguity aversion impact the level and structure of the optimal stock investment. Suboptimal strategies resulting either from not learning...

  8. Ambiguities in order-theoretic formulations of thermodynamics

    CERN Document Server

    Marsland, Robert; Valente, Giovanni

    2014-01-01

    Since the 1909 work of Carath\\'eodory, formulations of thermodynamics have gained ground which highlight the role of the the binary relation of adiabatic accessibility between equilibrium states. A feature of Carath\\'eodory's system is that the version therein of the second law contains an ambiguity about the nature of irreversible adiabatic processes, making it weaker than the traditional Kelvin-Planck statement of the law. This paper attempts first to clarify the nature of this ambiguity, by defining the arrow of time in thermodynamics by way of the Equilibrium Principle ("Minus First Law"). It then argues that the ambiguity reappears in the important 1999 axiomatisation due to Lieb and Yngvason.

  9. Characteristics of a pure-state ambiguity function

    Energy Technology Data Exchange (ETDEWEB)

    Praxmeyer, Ludmila; Vitanov, Nikolay [Department of Physics, Sofia University, James Bourchier 5 blvd, 1164 Sofia (Bulgaria); Stenholm, Stig [Physics Department, Royal Institute of Technology, KTH, Stockholm Sweden (Sweden)

    2009-12-11

    We present the necessary and sufficient condition for a square integrable function on R{sup 2N} to be an ambiguity function corresponding to a square integrable function on R{sup N}. This condition has the form of an integral equation. We also list some easier to check necessary conditions that must be fulfilled by a function that is an ambiguity function of a pure state. We show how to construct a wavefunction corresponding to a given ambiguity function and we present examples of how our formal results can be used in practice.

  10. Tool for Automatic Discovery of Ambiguity in Requirements

    Directory of Open Access Journals (Sweden)

    Neeraj Arya

    2012-09-01

    Full Text Available Requirements are the foundation for delivering quality software. Often it is found that the short development cycle lead teams to cut short the time they will spend on Requirement Analysis. In this work we developed a tool which can quickly review requirements by identifying ambiguous words and provide us the possible sources of wrong interpretation. Currently tool supports identification of Lexical, Syntactic and Syntax ambiguities. The tool will assist requirement analysis personnel while reviewing specifications, highlighting ambiguous words and providing graphical snapshot to gauge the correctness of documents.

  11. Who are you talking about? Tracking discourse-level referential processing with event-related brain potentials

    OpenAIRE

    Nieuwland, M.; Otten, M.; Berkum, J.

    2007-01-01

    In this event-related brain potentials (ERPs) study, we explored the possibility to selectively track referential ambiguity during spoken discourse comprehension. Earlier ERP research has shown that referentially ambiguous nouns (e.g., “the girl” in a two-girl context) elicit a frontal, sustained negative shift relative to unambiguous control words. In the current study, we examined whether this ERP effect reflects “deep” situation model ambiguity or “superficial” textbase ambiguity. We contr...

  12. On the matching of top-down knowledge with sensory input in the perception of ambiguous speech

    OpenAIRE

    Hannemann R; Eulitz C

    2010-01-01

    Abstract Background How does the brain repair obliterated speech and cope with acoustically ambivalent situations? A widely discussed possibility is to use top-down information for solving the ambiguity problem. In the case of speech, this may lead to a match of bottom-up sensory input with lexical expectations resulting in resonant states which are reflected in the induced gamma-band activity (GBA). Methods In the present EEG study, we compared the subject's pre-attentive GBA responses to ob...

  13. Conceptual knowledge representation: A cross-section of current research.

    Science.gov (United States)

    Rogers, Timothy T; Wolmetz, Michael

    2016-01-01

    How is conceptual knowledge encoded in the brain? This special issue of Cognitive Neuropsychology takes stock of current efforts to answer this question through a variety of methods and perspectives. Across this work, three questions recur, each fundamental to knowledge representation in the mind and brain. First, what are the elements of conceptual representation? Second, to what extent are conceptual representations embodied in sensory and motor systems? Third, how are conceptual representations shaped by context, especially linguistic context? In this introductory article we provide relevant background on these themes and introduce how they are addressed by our contributing authors. PMID:27454108

  14. Top-down influences on ambiguous perception: the role of stable and transient states of the observer

    Directory of Open Access Journals (Sweden)

    Lisa eScocchia

    2014-12-01

    Full Text Available The world as it appears to the viewer is the result of a complex process of inference performed by the brain. The validity of this apparently counter-intuitive assertion becomes evident whenever we face noisy, feeble or ambiguous visual stimulation: in these conditions, the state of the observer may play a decisive role in determining what is currently perceived. On this background, ambiguous perception and its amenability to top-down influences can be employed as an empirical paradigm to explore the principles of perception. Here we offer an overview of both classical and recent contributions on how stable and transient states of the observer can impact ambiguous perception. As to the influence of the stable states of the observer, we show that what is currently perceived can be influenced (1 by cognitive and affective aspects, such as meaning, prior knowledge, motivation and emotional content and (2 by individual differences, such as gender, handedness, genetic inheritance, clinical conditions and personality traits and by (3 learning and conditioning. As to the impact of transient states of the observer, we outline the effects of (4 attention and (5 voluntary control, which have attracted much empirical work along the history of ambiguous perception. In the huge literature on the topic we trace a difference between the observer’s ability to control dominance (i.e: the maintenance of a specific percept in visual awareness and reversal rate (i.e: the switching between two alternative percepts. Other transient states of the observer that have more recently drawn researchers’ attention regard (6 the effects of imagery and visual working memory. (7 Furthermore, we describe the transient effects of prior history of perceptual dominance. (8 Finally, we address the currently available computational models of ambiguous perception and how they can take into account the crucial share played by the state of the observer in perceiving ambiguous

  15. Unraveling the Symmetry Ambiguity in a Hexamer: Calculation of the R6 Human Insulin Structure

    DEFF Research Database (Denmark)

    O'Donoghue, Sean I.; Chang, Xiaoqing; Abseher, Roger;

    2000-01-01

    ambiguous distance restraints, insulin hexamer, principal component analysis, solution structure, symmetric oligomers......ambiguous distance restraints, insulin hexamer, principal component analysis, solution structure, symmetric oligomers...

  16. On the characteristics of ASCAT wind direction ambiguities

    Directory of Open Access Journals (Sweden)

    W. Lin

    2012-12-01

    Full Text Available The inversion of the Advanced Scatterometer (ASCAT backscatter measurement triplets generally leads to two wind ambiguities with similar wind speed values and opposite wind directions. However, for up-, down- and cross-wind (with respect to the mid beam azimuth direction cases, the inversion often leads to three or four wind solutions. In most of such cases, the inversion residual or maximum likelihood estimator (MLE of the 3rd and 4th solutions (i.e. high-rank solutions are substantially higher than those of the first two (low rank ambiguities, indicating a low probability of the former and thus essentially dual ambiguity. This paper investigates the characteristics of ASCAT high-rank wind solutions under different conditions with the objective to develop a method for rejecting the spurious high-rank solutions. The implementation of this rejection procedure improves the effectiveness of the ASCAT wind quality control (QC and ambiguity removal procedures.

  17. Ambiguous and forbidden parameter combinations for aqueous plutonium.

    Science.gov (United States)

    Silver, G L

    2009-01-01

    The concepts of forbidden and ambiguous oxidation-state distributions for plutonium are easier to understand when presented graphically. This note describes two diagrams that illustrate the phenomena. PMID:18986812

  18. Rapid integer ambiguity resolution in GPS precise point positioning

    OpenAIRE

    Geng, Jianghui

    2011-01-01

    GPS precise point positioning (PPP) has been used in many scientific and commercial applications due to its high computational efficiency, no need for any synchronous measurements from a nearby reference receiver and homogeneous positioning quality on a global scale. However, these merits are devalued significantly by unresolved ambiguities and slow convergences of PPP. Therefore, this thesis aims at improving PPP’s performance by resolving ambiguities for a single receiver and accelerating t...

  19. The clock ambiguity and the emergence of physical laws

    OpenAIRE

    Albrecht, Andreas; Iglesias, Alberto

    2007-01-01

    The process of identifying a time variable in time reparameterization invariant theories results in great ambiguities about the actual laws of physics described by a given theory. A theory set up to describe one set of physical laws can equally well be interpreted as describing any other laws of physics by making a different choice of time variable or ``clock''. In this article we demonstrate how this ``clock ambiguity'' arises and then discuss how one might still hope to extract specific pre...

  20. Ambiguity, Processing Strategy, and Advertising-Evidence Interactions.

    OpenAIRE

    Ha, Young-Won; Stephen J. Hoch

    1989-01-01

    Although advertising persuades through overt appeals to reason or emotion, we focus on the indirect process by which advertising influences the interpretation of objective product evidence. We investigate how two factors moderate advertising-evidence interactions: the ambiguity of the evidence and consumer information processing strategies. We provide a theoretical account of ambiguity, identifying structural characteristics that render evidence about product quality open to either one or mul...

  1. Minimizing the Integer Ambiguity Search Space for RTK

    Institute of Scientific and Technical Information of China (English)

    Yang Yun-chun; R. R. Hatch; R. T. Sharpe

    2003-01-01

    Differential GPS carrier phase measurements have much lower noise and multipath error than that of pseudorange measurements.The result is centimeter accuracy for Real-Time Kinematic (RTK).However, the measurement of the carrier phase has a constant unknown integer ambiguity. Several technical issues are related to solving the integer ambiguity correctly. They are: proper stochastic model, search space definition and initialization, search space reduction, state and standard deviation calculation, validation and rejection criteria for the unique and correct candidate. Search space reduction is critically important. It not only affects the ambiguity resolution speed, but also defines the ambiguity resolution success rate. The smaller the search space, the easier it is to find the unique and correct candidate set. The paper analyzes the integer ambiguity search space in its residual domain.The search space is minimized by: Analyzing the maximum independent integer ambiguity measurement set theoretically; Selecting the best initial measurement set that minimizes the search range of each satellite in the set and reduces the error effects from noise that may cause the wrong integer ambiguity solution for the remaining satellites not contained in the initial measurement set.Since the Residual Sensitive Matrix (S-Matrix) relates the integer ambiguity candidate set directly to post-fix residuals, it is not necessary to compute a fix for each candidate set thus making the integ erambiguity search process much more efficient. Also, minimizing the search space in the residual domain improves the search efficiency significantly and at the same time improves its reliability. Performance issues, such as recursive and weighted search techniques as well as methods for improving reliability, are also discussed in the article.

  2. Word segmentation of overlapping ambiguous strings during Chinese reading

    OpenAIRE

    Ma, Guojie; Li, Xingshan; Rayner, Keith

    2014-01-01

    In three experiments, we tested three possible mechanisms for segmenting overlapping ambiguous strings in Chinese reading. The first two characters and the last two characters in a 3-character ambiguous string could both constitute a word in the reported studies. The left-priority hypothesis assumes that the word on the left has an advantage in the competition and the other word cannot be processed until the word on the left is recognized. The independent processing hypothesis assumes that wo...

  3. Neural Correlates of Semantic Competition during Processing of Ambiguous Words

    OpenAIRE

    Bilenko, Natalia Y.; Grindrod, Christopher M.; Myers, Emily B.; Blumstein, Sheila E.

    2009-01-01

    The current study investigated the neural correlates that underlie the processing of ambiguous words and the potential effects of semantic competition on that processing. Participants performed speeded lexical decisions on semantically related and unrelated prime-target pairs presented in the auditory modality. The primes were either ambiguous words (e.g., ball) or unambiguous words (e.g., athlete), and targets were either semantically related to the dominant (i.e., most frequent) meaning of ...

  4. Tool for Automatic Discovery of Ambiguity in Requirements

    OpenAIRE

    Neeraj Arya; Bhawna Nigam; Deepika Jain; Ayan Nigam

    2012-01-01

    Requirements are the foundation for delivering quality software. Often it is found that the short development cycle lead teams to cut short the time they will spend on Requirement Analysis. In this work we developed a tool which can quickly review requirements by identifying ambiguous words and provide us the possible sources of wrong interpretation. Currently tool supports identification of Lexical, Syntactic and Syntax ambiguities. The tool will assist requirement analysis personnel while r...

  5. The interpretation of ambiguous trimorphemic words in sentence context

    OpenAIRE

    Pollatsek, Alexander; Drieghe, Denis; Stockall, Linnaea; de Almeida, Roberto

    2010-01-01

    Many trimorphemic words are structurally and semantically ambiguous. For example, unlockable can either be un-lockable (can’t be locked) or unlock-able (can be unlocked). Which interpretation is preferred and whether prior sentence context affects the initial interpretation is not clear from prior research. The present experiment embedded ambiguous trimorphemic words in sentence context and manipulated whether prior context disambiguated the meaning or not and examined the pattern of fixation...

  6. Isoclinic Ambiguity Unwrapping of Circular Ring under Diametric Compression

    Directory of Open Access Journals (Sweden)

    Huang M.-J.

    2010-06-01

    Full Text Available Isoclinic and isochromatic parameters in photoelastic analysis are formulated by arc tangent function of several phase shifting frames but for isochromatic calculation it is, in addition, in terms of isoclinic data also. Thus, any isoclinic phase ambiguity would also result in the phase inconsistencies of isochromatic calculation and cause unwrapping problems and difficulties. Many methods had been proposed to treat these kinds of isochromatic fringes but lots of treatments were needed for the correct retrieval. In this work, the isoclinic ambiguity problem is investigated and solved directly by a novel regional phase unwrapping technique. Once the isoclinic phase ambiguity problems are solved, a correct isoclinic result can be obtained. Then, substituting this result into the isochromatic formation yields an ambiguity free isochromatic phase map, which can be easily restored by any phase unwrapping algorithm. A stress frozen sample - circular ring under diametric compression verifies its effectiveness. Usually happened is that this kind of sample is with ambiguous isoclinic data which would cause phase ambiguities of the isochromatic formulation if not treated well first.

  7. Removing Ambiguities of IP Telephony Traffic Using Protocol Scrubbers

    Directory of Open Access Journals (Sweden)

    Bazara I. A. Barry

    2012-10-01

    Full Text Available Network intrusion detection systems (NIDSs face the serious challenge of attacks such as insertion and evasion attacks that are caused by ambiguous network traffic. Such ambiguity comes as a result of the nature of network traffic which includes protocol implementation variations and errors alongside legitimate network traffic. Moreover, attackers can intentionally introduce further ambiguities in the traffic. Consequently, NIDSs need to be aware of these ambiguities when detection is performed and make sure to differentiate between true attacks and protocol implementation variations or errors; otherwise, detection accuracy can be affected negatively. In this paper we present the design and implementation of tools that are called protocol scrubbers whose main functionality is to remove ambiguities from network traffic before it is presented to the NIDS. The proposed protocol scrubbers are designed for session initiation and data transfer protocols in IP telephony systems. They guarantee that the traffic presented to NIDSs is unambiguous by eliminating ambiguous behaviors of protocols using well-designed protocol state machines, and walking through packet headers of protocols to make sure packets will be interpreted in the desired way by the NIDS. The experimental results shown in this paper demonstrate the good quality and applicability of the introduced scrubbers.

  8. Multimodal Brain Visualization

    OpenAIRE

    Nadeem, Saad; Kaufman, Arie

    2016-01-01

    Current connectivity diagrams of human brain image data are either overly complex or overly simplistic. In this work we introduce simple yet accurate interactive visual representations of multiple brain image structures and the connectivity among them. We map cortical surfaces extracted from human brain magnetic resonance imaging (MRI) data onto 2D surfaces that preserve shape (angle), extent (area), and spatial (neighborhood) information for 2D (circular disk) and 3D (spherical) mapping, spl...

  9. Compositional connectionist structures based on in situ grounded representations

    NARCIS (Netherlands)

    Velde, van der Frank; Kamps, de Marc

    2011-01-01

    The combination of productivity, dynamics and grounding imposes constraints that require specific architectures for their combined implementation. Grounding of representations can be achieved with specific neuronal assembly structures, which can be distributed over different brain areas. This entail

  10. The Usability of Ambiguity Detection Methods for Context-Free Grammars

    NARCIS (Netherlands)

    Basten, H.J.S.; Johnstone, A.; Vinju, J.J.

    2008-01-01

    One way of verifying a grammar is the detection of ambiguities. Ambiguities are not always unwanted, but they can only be controlled if their sources are known. Unfortunately, the ambiguity problem for context-free grammars is undecidable in the general case. Various ambiguity detection methods (ADM

  11. Learning Deep Face Representation

    OpenAIRE

    Fan, Haoqiang; Cao, Zhimin; Jiang, Yuning; Yin, Qi; Doudou, Chinchilla

    2014-01-01

    Face representation is a crucial step of face recognition systems. An optimal face representation should be discriminative, robust, compact, and very easy-to-implement. While numerous hand-crafted and learning-based representations have been proposed, considerable room for improvement is still present. In this paper, we present a very easy-to-implement deep learning framework for face representation. Our method bases on a new structure of deep network (called Pyramid CNN). The proposed Pyrami...

  12. Normalized neural representations of natural odors

    CERN Document Server

    Zwicker, David

    2016-01-01

    The olfactory system removes correlations in natural odors using a network of inhibitory neurons in the olfactory bulb. It has been proposed that this network integrates the response from all olfactory receptors and inhibits them equally. However, how such global inhibition influences the neural representations of odors is unclear. Here, we study a simple statistical model of this situation, which leads to concentration-invariant, sparse representations of the odor composition. We show that the inhibition strength can be tuned to obtain sparse representations that are still useful to discriminate odors that vary in relative concentration, size, and composition. The model reveals two generic consequences of global inhibition: (i) odors with many molecular species are more difficult to discriminate and (ii) receptor arrays with heterogeneous sensitivities perform badly. Our work can thus help to understand how global inhibition shapes normalized odor representations for further processing in the brain.

  13. Value transfer contributes to ambiguous-cue discrimination learning.

    Science.gov (United States)

    Urcuioli, Peter J; Michalek, Sarah

    2007-08-01

    Pigeons learned two concurrent simultaneous discriminations in which the S- for one served as the S+ for the other. When all correct choices were reinforced, accuracy on the former (positive vs. ambiguous-cue or PA) discrimination was lower than on the latter (negative vs. ambiguous-cue or NA) discrimination. When correct choices on the PA discrimination were intermittently reinforced, however, pigeons chose the S- more often than the S+ on those trials. By contrast, intermittently reinforcing correct choices on the NA discrimination did not affect NA-trial accuracy but yielded higher PA-trial accuracy relative to continuous reinforcement. Together with a separate preference assessment, these results indicate that value transfer, in which some of the positive value accrued by an S+ transfers to its companion S-, contributes to ambiguous-cue performances. PMID:17972729

  14. CSR and the Mediated Emergence of Strategic Ambiguity

    DEFF Research Database (Denmark)

    Guthey, Eric; Morsing, Mette

    2014-01-01

    We develop a framework for understanding how lack of clarity in business press coverage of corporate social responsibility functions as a mediated and emergent form of strategic ambiguity. Many stakeholders expect CSR to exhibit clarity, consistency, and discursive closure. But stakeholders also...... expect CSR to conform to varying degrees of both formal and substantive rationality. These diverse expectations conflict with each other and change over time. A content analysis of press coverage in Denmark suggests that the business media reflect and amplify the ambiguity generated by these shifting...... demands. We propose that this very public lack of discursive closure provides strategic advantages to CSR stakeholders by rendering the concept of CSR adaptable, resilient, and meaningful to diverse interests. From this perspective, strategic ambiguity emerges from a relational and mediated process...

  15. Word segmentation of overlapping ambiguous strings during Chinese reading.

    Science.gov (United States)

    Ma, Guojie; Li, Xingshan; Rayner, Keith

    2014-06-01

    In 3 experiments, we tested 3 possible mechanisms for segmenting overlapping ambiguous strings in Chinese reading. The first 2 characters and the last 2 characters in a 3-character ambiguous string could both constitute a word in the reported studies. The left-priority hypothesis assumes that the word on the left has an advantage in the competition and the other word cannot be processed until the word on the left is recognized. The independent processing hypothesis assumes that words in different positions are processed simultaneously and independently, and the word segmentation ambiguity cannot be settled without the help of sentence context. The competition hypothesis assumes that all of the words compete for a single winner. The results support a competition account that the characters in the perceptual span activate all of the words they can constitute, and any word can win the competition if its activation is high enough. PMID:24417292

  16. Value transfer contributes to ambiguous-cue discrimination learning.

    Science.gov (United States)

    Urcuioli, Peter J; Michalek, Sarah

    2007-08-01

    Pigeons learned two concurrent simultaneous discriminations in which the S- for one served as the S+ for the other. When all correct choices were reinforced, accuracy on the former (positive vs. ambiguous-cue or PA) discrimination was lower than on the latter (negative vs. ambiguous-cue or NA) discrimination. When correct choices on the PA discrimination were intermittently reinforced, however, pigeons chose the S- more often than the S+ on those trials. By contrast, intermittently reinforcing correct choices on the NA discrimination did not affect NA-trial accuracy but yielded higher PA-trial accuracy relative to continuous reinforcement. Together with a separate preference assessment, these results indicate that value transfer, in which some of the positive value accrued by an S+ transfers to its companion S-, contributes to ambiguous-cue performances.

  17. Text Association Analysis and Ambiguity in Text Mining

    Science.gov (United States)

    Bhonde, S. B.; Paikrao, R. L.; Rahane, K. U.

    2010-11-01

    Text Mining is the process of analyzing a semantically rich document or set of documents to understand the content and meaning of the information they contain. The research in Text Mining will enhance human's ability to process massive quantities of information, and it has high commercial values. Firstly, the paper discusses the introduction of TM its definition and then gives an overview of the process of text mining and the applications. Up to now, not much research in text mining especially in concept/entity extraction has focused on the ambiguity problem. This paper addresses ambiguity issues in natural language texts, and presents a new technique for resolving ambiguity problem in extracting concept/entity from texts. In the end, it shows the importance of TM in knowledge discovery and highlights the up-coming challenges of document mining and the opportunities it offers.

  18. Improving integer ambiguity resolution for GLONASS precise orbit determination

    Science.gov (United States)

    Liu, Yang; Ge, Maorong; Shi, Chuang; Lou, Yidong; Wickert, Jens; Schuh, Harald

    2016-08-01

    The frequency division multiple access adopted in present GLONASS introduces inter-frequency bias (IFB) at the receiver-end both in code and phase observables, which makes GLONASS ambiguity resolution rather difficult or even not available, especially for long baselines up to several thousand kilometers. This is one of the major reasons that GLONASS could hardly reach the orbit precision of GPS, both in terms of consistency among individual International GNSS Service (IGS) analysis centers and discontinuity at the overlapping day boundaries. Based on the fact that the GLONASS phase IFB is similar on L1 and L2 bands in unit of length and is a linear function of the frequency number, several approaches have been developed to estimate and calibrate the IFB for integer ambiguity resolution. However, they are only for short and medium baselines. In this study, a new ambiguity resolution approach is developed for GLONASS global networks. In the approach, the phase ambiguities in the ionosphere-free linear combination are directly transformed with a wavelength of about 5.3 cm, according to the special frequency relationship of GLONASS L1 and L2 signals. After such transformation, the phase IFB rate can be estimated and corrected precisely and then the corresponding double-differenced ambiguities can be directly fixed to integers even for baselines up to several thousand kilometers. To evaluate this approach, experimental validations using one-month data of a global network with 140 IGS stations was carried out for GLONASS precise orbit determination. The results show that the GLONASS double-difference ambiguity resolution for long baselines could be achieved with an average fixing-rate of 91.4 %. Applying the fixed ambiguities as constraints, the GLONASS orbit overlapping RMS at the day boundaries could be reduced by 37.2 % in ideal cases and with an averaged reduction of about 21.4 %, which is comparable with that by the GPS ambiguity resolution. The orbit improvement is

  19. Distinguishing Representations as Origin and Representations as Input: Roles for Individual Neurons

    Science.gov (United States)

    Edwards, Jonathan C. W.

    2016-01-01

    in an input interaction between signals and consumer. The acceptance of this necessity provides a basis for resolving the problem that representations appear both as distributed (representation-as-origin) and as local (representation-as-input). The key implications are that representations in the brain are massively multiple both in series and in parallel, and that individual cells play specific semantic roles. These roles are discussed in relation to traditional concepts of ‘gnostic’ cell types. PMID:27746760

  20. Neural Representations of Physics Concepts.

    Science.gov (United States)

    Mason, Robert A; Just, Marcel Adam

    2016-06-01

    We used functional MRI (fMRI) to assess neural representations of physics concepts (momentum, energy, etc.) in juniors, seniors, and graduate students majoring in physics or engineering. Our goal was to identify the underlying neural dimensions of these representations. Using factor analysis to reduce the number of dimensions of activation, we obtained four physics-related factors that were mapped to sets of voxels. The four factors were interpretable as causal motion visualization, periodicity, algebraic form, and energy flow. The individual concepts were identifiable from their fMRI signatures with a mean rank accuracy of .75 using a machine-learning (multivoxel) classifier. Furthermore, there was commonality in participants' neural representation of physics; a classifier trained on data from all but one participant identified the concepts in the left-out participant (mean accuracy = .71 across all nine participant samples). The findings indicate that abstract scientific concepts acquired in an educational setting evoke activation patterns that are identifiable and common, indicating that science education builds abstract knowledge using inherent, repurposed brain systems.

  1. Neural Representations of Physics Concepts.

    Science.gov (United States)

    Mason, Robert A; Just, Marcel Adam

    2016-06-01

    We used functional MRI (fMRI) to assess neural representations of physics concepts (momentum, energy, etc.) in juniors, seniors, and graduate students majoring in physics or engineering. Our goal was to identify the underlying neural dimensions of these representations. Using factor analysis to reduce the number of dimensions of activation, we obtained four physics-related factors that were mapped to sets of voxels. The four factors were interpretable as causal motion visualization, periodicity, algebraic form, and energy flow. The individual concepts were identifiable from their fMRI signatures with a mean rank accuracy of .75 using a machine-learning (multivoxel) classifier. Furthermore, there was commonality in participants' neural representation of physics; a classifier trained on data from all but one participant identified the concepts in the left-out participant (mean accuracy = .71 across all nine participant samples). The findings indicate that abstract scientific concepts acquired in an educational setting evoke activation patterns that are identifiable and common, indicating that science education builds abstract knowledge using inherent, repurposed brain systems. PMID:27113732

  2. Tracking down abstract linguistic meaning: neural correlates of spatial frame of reference ambiguities in language.

    Directory of Open Access Journals (Sweden)

    Gabriele Janzen

    Full Text Available This functional magnetic resonance imaging (fMRI study investigates a crucial parameter in spatial description, namely variants in the frame of reference chosen. Two frames of reference are available in European languages for the description of small-scale assemblages, namely the intrinsic (or object-oriented frame and the relative (or egocentric frame. We showed participants a sentence such as "the ball is in front of the man", ambiguous between the two frames, and then a picture of a scene with a ball and a man--participants had to respond by indicating whether the picture did or did not match the sentence. There were two blocks, in which we induced each frame of reference by feedback. Thus for the crucial test items, participants saw exactly the same sentence and the same picture but now from one perspective, now the other. Using this method, we were able to precisely pinpoint the pattern of neural activation associated with each linguistic interpretation of the ambiguity, while holding the perceptual stimuli constant. Increased brain activity in bilateral parahippocampal gyrus was associated with the intrinsic frame of reference whereas increased activity in the right superior frontal gyrus and in the parietal lobe was observed for the relative frame of reference. The study is among the few to show a distinctive pattern of neural activation for an abstract yet specific semantic parameter in language. It shows with special clarity the nature of the neural substrate supporting each frame of spatial reference.

  3. Event-related potentials indicate context effect in reading ambiguous words.

    Science.gov (United States)

    Kotchoubey, Boris; El-Khoury, Sylvain

    2014-10-29

    The aim of the study was a comparison of lexical and contextual factors in understanding ambiguous words in German. First, a sample of native speakers selected 56 words having maximally strong differences between a dominant and a subordinate meaning. After this, another sample from the same population was visually presented with sentences that activated dominant or subordinate meanings of the words and were accompanied by probes associated with dominant or subordinate meanings. This resulted in a crossed design with two factors: sentence dominant vs. sentence subordinate and probe dominant vs. probe subordinate. An analysis of event-related brain potentials revealed a large, long-lasting and highly-significant N400 wave whenever the meaning of the probe was incongruent with the meaning of the sentence and the lack of this wave whenever the two meanings were congruent. In the typical N400 space and time, the effect was independent of whether the lexical word meaning was dominant or subordinate. At other sites and times, however (e.g., at lateral frontal electrodes F7/F8, and after 700ms), the congruence effect was significant after dominant sentences only. The data indicate that lexical factors have a rather limited influence on the activation of a particular meaning of ambiguous words. A strong context can virtually override even a very strong difference in the preference for different meanings. PMID:25463139

  4. How to Capture and Present Complexity, Ambivalence and Ambiguity

    DEFF Research Database (Denmark)

    Ooi, Can-Seng

    Bakhtin was a literary theorist and was the widely acknowledged father of dialogism. This working paper shows how Bakhtin and dialogism can be used to capture complexity, ambivalence and ambiguity in the social world. In following the spirit of dialogism, I will refer to my own research experiences...

  5. Handling Ambiguity Problems of Natural Language Interface for Question Answering

    Directory of Open Access Journals (Sweden)

    Omar Alharbi

    2012-05-01

    Full Text Available The Natural language question (NLQ processing module is considered a fundamental component in the natural language interface of a Question Answering (QA system, and its quality impacts the performance of the overall QA system. The most difficult problem in developing a QA system is so hard to find an exact answer to the NLQ. One of the most challenging problems in returning answers is how to resolve lexical semantic ambiguity in the NLQs. Lexical semantic ambiguity may occurs when a user's NLQ contains words that have more than one meaning. As a result, QA system performance can be negatively affected by these ambiguous words. In this research, we aim to resolve this problem by introducing CKCO (Context Knowledge Concepts Ontology approach. This approach integrates context knowledge and concepts ontology of a domain, into a shallow natural language processing (SNLP technique. Concepts knowledge is modeled using ontology, while context knowledge contains a set of words with their senses obtained from WordNet Domain and a group of words within the proposed domain serve as context labels, and it is determined based on neighborhood words in the NLQ. We applied CKCO approach to a university QA domain for new students to examine the impact of WSD in retrieving correct answers. Experimental results show that the CKCO approach together with other components of our QA system yield a result which is 83.4% for precision. We focus on the ambiguity of nouns in the NLQ.

  6. A Mindfulness Experiential Small Group to Help Students Tolerate Ambiguity

    Science.gov (United States)

    Bohecker, Lynn; Vereen, Linwood G.; Wells, Pamela C.; Wathen, Cristen C.

    2016-01-01

    This study explored the lived experiences of 20 counselors-in-training (CITs) in a mindfulness experiential small group. Using grounded theory, the authors described a 5-dimensional model for navigating ambiguity. Findings suggest mindfulness training provides CITs self-reflection skills and a greater ability to manage cognitive complexity.

  7. What Is Reflection? Looking for Clarity in an Ambiguous Notion

    Science.gov (United States)

    Clarà, Marc

    2015-01-01

    The notion of reflection nowadays is considered crucial in the field of teaching and teacher education. However, although the great majority of approaches to reflection are grounded on the same main theoretical sources, the meaning of this notion is unanimously recognized in the field to be ambiguous. This article aims to look for clarity about…

  8. Ambiguities of arrival-time distributions in quantum theory

    OpenAIRE

    Finkelstein, J

    1998-01-01

    We consider the definition that might be given to the time at which a particle arrives at a given place, both in standard quantum theory and also in Bohmian mechanics. We discuss an ambiguity that arises in the standard theory in three, but not in one, spatial dimension.

  9. Clock ambiguity and the emergence of physical laws

    International Nuclear Information System (INIS)

    The process of identifying a time variable in time-reparameterization invariant theories results in great ambiguities about the actual laws of physics described by a given theory. A theory set up to describe one set of physical laws can equally well be interpreted as describing any other laws of physics by making a different choice of time variable or clock. In this article we demonstrate how this 'clock ambiguity' arises and then discuss how one might still hope to extract specific predictions about the laws of physics even when the clock ambiguity is present. We argue that a requirement of quasiseparability should play a critical role in such an analysis. As a step in this direction, we compare the Hamiltonian of a local quantum field theory with a completely random Hamiltonian. We find that any random Hamiltonian (constructed in a sufficiently large space) can yield a 'good enough' approximation to a local field theory. Based on this result we argue that theories that suffer from the clock ambiguity may in the end provide a viable fundamental framework for physics in which locality can be seen as a strongly favored (or predicted) emergent behavior. We also speculate on how other key aspects of known physics such as gauge symmetries and Poincare invariance might be predicted to emerge in this framework.

  10. Ambiguity of the equivalence principle and Hawking's temperature

    OpenAIRE

    Hooft, G. 't

    1984-01-01

    There are two inequivalent ways in which the laws of physics in a gravitational field can be related to the laws in an inertial frame, when quantum mechanical effects are taken into account. This leads to an ambiguity in the derivation of Hawking's radiation temperature for a black hole: it could be twice the value usually considered.

  11. Ambiguity Aversion and Household Portfolio Choice Puzzles: Empirical Evidence

    NARCIS (Netherlands)

    S.G. Dimmock (Stephen); R.R.P. Kouwenberg (Roy); O.S. Mitchell (Olivia); K. Peijnenburg (Kim)

    2016-01-01

    markdownabstractWe test the relation between ambiguity aversion and five household portfolio choice puzzles: nonparticipation in equities, low allocations to equity, home-bias, own-company stock ownership, and portfolio under-diversification. In a representative US household survey, we measure ambig

  12. Prosody and the Interpretation of Hierarchically Ambiguous Discourse

    Science.gov (United States)

    Tyler, Joseph

    2014-01-01

    Although significant attention has been devoted to prosody in discourse production, relatively little is known about prosody's effect on discourse interpretation. This article explores the ability of synthetic manipulations of prosody to bias interpretation of discourse ambiguities where a first sentence is linked to two following sentences…

  13. Is Multilingualism Linked to a Higher Tolerance of Ambiguity?

    Science.gov (United States)

    DeWaele, Jean-Marc; Wei, Li

    2013-01-01

    The present study investigates the link between multilingualism and the personality trait Tolerance of Ambiguity (TA) among 2158 mono-, bi- and multilinguals. Monolinguals and bilinguals scored significantly lower on TA compared to multilinguals. A high level of global proficiency of various languages was linked to higher TA scores. A stay abroad…

  14. GNSS integer ambiguity validation based on posterior probability

    Science.gov (United States)

    Wu, Zemin; Bian, Shaofeng

    2015-10-01

    GNSS integer ambiguity validation is considered to be a challenge task for decades. Several kinds of validation tests are developed and widely used in these years, but theoretical basis is their weakness. Ambiguity validation theoretically is an issue of hypothesis test. In the frame of Bayesian hypothesis testing, posterior probability is the canonical standard that statistical decision should be based on. In this contribution, (i) we derive the posterior probability of the fixed ambiguity based on the Bayesian principle and modify it for practice ambiguity validation. (ii) The optimal property of the posterior probability test is proved based on an extended Neyman-Pearson lemma. Since validation failure rate is the issue users most concerned about, (iii) we derive the failure rate upper bound of the posterior probability test, so the user can use the posterior probability test either in the fixed posterior probability or in the fixed failure rate way. Simulated as well as real observed data are used for experimental validations. The results show that (i) the posterior probability test is the most effective within the R-ratio test, difference test, ellipsoidal integer aperture test and posterior probability test, (ii) the posterior probability test is computational efficient and (iii) the failure rate estimation for posterior probability test is useful.

  15. Three to six ambiguities in immittance spectroscopy data fitting.

    Science.gov (United States)

    Macdonald, J Ross

    2012-05-01

    Several important ambiguities in immittance spectroscopy (IS) model data-fitting results are identified and illustrated by means of complex-nonlinear-least-squares (CNLS) fits of experimental and synthetic frequency response data. A well-known intrinsic ambiguity, following from Maxwell's electromagnetic equations, arises from the indistinguishability in external measurements of conduction and displacement currents. Usual fit models for either dielectric or conductive-system situations, such as the Davidson-Cole one, only involve a strength parameter, a dielectric constant, a characteristic relaxation time, and a fractional exponent and lead to no additional ambiguities. But the situation is different for more powerful and useful general models, such as ordinary or anomalous diffusion Poisson-Nernst-Planck ones: PNP and PNPA, used here, whose historical background, current status, and applicability are described and discussed herein. They apply to two different kinds of experimental IS situations and involve several additional, potentially free fit parameters, such as the mobilities of positive and negative charge carriers, and generation-recombination parameters that determine the partial or complete dissociation of a neutral entity of concentration N(0) into positive and negative charge carriers of equal concentration, c(0). Then, several additional ambiguities appear that may require information about the material system involved for their adequate resolution. PMID:22481085

  16. Bidirectional Transfer: Consequences of Translation Ambiguity for Bilingual Word Meaning

    Science.gov (United States)

    Degani, Tamar

    2011-01-01

    Could a second language (L2) influence how bilinguals process their native language (L1)? The work described in this dissertation examined this issue focusing on the way bilinguals interpret the meanings of words. Capitalizing on the prevalence of words that can be translated in more than one way across languages (i.e., "translation ambiguity,"…

  17. Interpretation of Ambiguous Information in Girls at Risk for Depression

    OpenAIRE

    Dearing, Karen F.; Gotlib, Ian H.

    2009-01-01

    Research has consistently documented that depressed individuals process information in a negatively biased manner. There is little evidence, however, concerning whether these biases represent risk factors for depression, as is hypothesized by cognitive models. In the present study we investigated whether a particular cognitive bias observed in currently depressed individuals, the tendency to interpret ambiguous information negatively, characterizes daughters of depressed mothers, a population...

  18. Neural Correlates of Semantic Competition during Processing of Ambiguous Words

    Science.gov (United States)

    Bilenko, Natalia Y.; Grindrod, Christopher M.; Myers, Emily B.; Blumstein, Sheila E.

    2009-01-01

    The current study investigated the neural correlates that underlie the processing of ambiguous words and the potential effects of semantic competition on that processing. Participants performed speeded lexical decisions on semantically related and unrelated prime-target pairs presented in the auditory modality. The primes were either ambiguous…

  19. Resolving distance ambiguities towards 6.7 GHz methanol masers

    CERN Document Server

    Pandian, J D; Goldsmith, P F

    2008-01-01

    Distances to most star forming regions are determined using kinematics, through the assumption that the observed radial velocity arises from the motion of the source with respect to the Sun resulting from the differential rotation of Galaxy. The primary challenge associated with the application of this technique in the inner Galaxy is the kinematic distance ambiguity. In this work, we aim to resolve the kinematic distance ambiguity towards a sample of 6.7 GHz methanol masers, which are signposts of the early stages of massive star formation. We measured 21 cm HI absorption spectra using the Very Large Array in C and CnB configurations. A comparison of the maximum velocity of HI absorption with the source velocity and tangent point velocity was used to resolve the kinematic distance ambiguity. We resolved the distance ambiguity towards 41 sources. Distance determinations that are in conflict with previous measurements are discussed. The NE2001 spiral arm model is broadly consistent with the locations of the st...

  20. Psychometric Analysis of Role Conflict and Ambiguity Scales in Academia

    Science.gov (United States)

    Khan, Anwar; Yusoff, Rosman Bin Md.; Khan, Muhammad Muddassar; Yasir, Muhammad; Khan, Faisal

    2014-01-01

    A comprehensive Psychometric Analysis of Rizzo et al.'s (1970) Role Conflict & Ambiguity (RCA) scales were performed after its distribution among 600 academic staff working in six universities of Pakistan. The reliability analysis includes calculation of Cronbach Alpha Coefficients and Inter-Items statistics, whereas validity was determined by…

  1. Exploiting Network Topology Information to Mitigate Ambiguities in VMP Localization

    DEFF Research Database (Denmark)

    Pedersen, Claus; Pedersen, Troels; Fleury, Bernard Henri

    2011-01-01

    We investigate an extension to the probabilistic model of a wireless sensor network (WSN) in the variational message passing localization algorithm. This extension exploits network topology information to mitigate ambiguities in WSN localization schemes. In a simulation case study we show...

  2. Persistence of Initial Misanalysis With No Referential Ambiguity.

    Science.gov (United States)

    Nakamura, Chie; Arai, Manabu

    2016-05-01

    Previous research reported that in processing structurally ambiguous sentences comprehenders often preserve an initial incorrect analysis even after adopting a correct analysis following structural disambiguation. One criticism is that the sentences tested in previous studies involved referential ambiguity and allowed comprehenders to make inferences about the initial interpretation using pragmatic information, suggesting the possibility that the initial analysis persisted due to comprehenders' pragmatic inference but not to their failure to perform complete reanalysis of the initial misanalysis. Our study investigated this by testing locally ambiguous relative clause sentences in Japanese, in which the initial misinterpretation contradicts the correct interpretation. Our study using a self-paced reading technique demonstrated evidence for the persistence of the initial analysis with this structure. The results from an eye-tracking study further suggested that the phenomenon directly reflected the amount of support given to the initial incorrect analysis prior to disambiguating information: The more supported the incorrect main clause analysis was, the more likely comprehenders were to preserve the analysis even after the analysis was falsified. Our results thus demonstrated that the preservation of the initial analysis occurs not due to referential ambiguities but to comprehenders' difficulty to fully revise the highly supported initial interpretation.

  3. Auditory scene analysis: The sweet music of ambiguity

    Directory of Open Access Journals (Sweden)

    Daniel ePressnitzer

    2011-12-01

    Full Text Available In this review paper aimed at the non-specialist, we explore the use that neuroscientists and musicians have made of perceptual illusions based on ambiguity. The pivotal issue is auditory scene analysis, or what enables us to make sense of complex acoustic mixtures in order to follow, for instance, a single melody in the midst of an orchestra. In general, auditory scene analysis uncovers the most likely physical causes that account for the waveform collected at the ears. However, the acoustical problem is ill-posed and it must be solved from noisy sensory input. Recently, the neural mechanisms implicated in the transformation of ambiguous sensory information into coherent auditory scenes have been investigated using so-called bistability illusions (where an unchanging ambiguous stimulus evokes a succession of distinct percepts in the mind of the listener. After reviewing some of those studies, we turn to music, which arguably provides some of the most complex acoustic scenes that a human listener will ever encounter. Interestingly, musicians will not always aim at making each physical source intelligible, but rather to express one or more melodic lines with a small or large number of instruments. By means of a few musical illustrations and by using a computational model inspired by neuro-physiological principles, we suggest that this relies on a detailed (if perhaps implicit knowledge of the rules of auditory scene analysis and of its inherent ambiguity. We then put forward the opinion that some degree perceptual ambiguity may participate in our appreciation of music.

  4. European starlings unriddle the ambiguous-cue problem

    Directory of Open Access Journals (Sweden)

    Marco eVasconcelos

    2014-08-01

    Full Text Available The ambiguous-cue problem is deceptively simple. It involves two concurrently trained simultaneous discriminations (known as PA and NA trials, but only three stimuli. Stimulus A is common to both discriminations, but serves as non-reinforced stimulus (S- on PA trials and as reinforced stimulus (S+ on NA trials. Typically, animals’ accuracy is lower on PA trials—the ambiguous-cue effect. We conducted two experiments with European starlings (Sturnus vulgaris using Urcuioli and Michalek’s [2007, Psychon B Rev 14, 658-662] experimental manipulations as a springboard to test the predictions of two of the most important theoretical accounts of the effect: the interfering cue hypothesis and value transfer theory. Both experiments included two groups of birds, one trained with a regular ambiguous-cue problem (Group Continuous and another trained with partial reinforcement on PA trials (Group PA-Partial. The experiments differed only in the number of sessions (18 vs. 36 and daily trials (360 vs. 60. As previously observed, we found faster acquisition on NA trials than on PA trials in both experiments, but by the end of training PA performance was surprisingly high, such that no ambiguous-cue effect was present in Group Continuous of either experiment. The effect was still present in both PA-Partial groups, but to a smaller degree than expected. These findings are inconsistent with the literature, in particular with the results of Urcuioli and Michalek with pigeons, and question the aforementioned theoretical accounts as complete explanations of the ambiguous-cue effect. In our view, to achieve such high levels of accuracy on PA trials, starlings must have attended to configural (i.e., contextual cues, thus differentiating stimulus A when presented on PA trials from stimulus A when presented on NA trials. A post hoc simulation of a reinforcement-based configural model supported our assertion.

  5. XML-BASED REPRESENTATION

    Energy Technology Data Exchange (ETDEWEB)

    R. KELSEY

    2001-02-01

    For focused applications with limited user and use application communities, XML can be the right choice for representation. It is easy to use, maintain, and extend and enjoys wide support in commercial and research sectors. When the knowledge and information to be represented is object-based and use of that knowledge and information is a high priority, then XML-based representation should be considered. This paper discusses some of the issues involved in using XML-based representation and presents an example application that successfully uses an XML-based representation.

  6. Visual representations are dominated by intrinsic fluctuations correlated between areas

    Science.gov (United States)

    Henriksson, Linda; Khaligh-Razavi, Seyed-Mahdi; Kay, Kendrick; Kriegeskorte, Nikolaus

    2015-01-01

    Intrinsic cortical dynamics are thought to underlie trial-to-trial variability of visually evoked responses in animal models. Understanding their function in the context of sensory processing and representation is a major current challenge. Here we report that intrinsic cortical dynamics strongly affect the representational geometry of a brain region, as reflected in response-pattern dissimilarities, and exaggerate the similarity of representations between brain regions. We characterized the representations in several human visual areas by representational dissimilarity matrices (RDMs) constructed from fMRI response-patterns for natural image stimuli. The RDMs of different visual areas were highly similar when the response-patterns were estimated on the basis of the same trials (sharing intrinsic cortical dynamics), and quite distinct when patterns were estimated on the basis of separate trials (sharing only the stimulus-driven component). We show that the greater similarity of the representational geometries can be explained by coherent fluctuations of regional-mean activation within visual cortex, reflecting intrinsic dynamics. Using separate trials to study stimulus-driven representations revealed clearer distinctions between the representational geometries: a Gabor wavelet pyramid model explained representational geometry in visual areas V1–3 and a categorical animate–inanimate model in the object-responsive lateral occipital cortex. PMID:25896934

  7. Syntactic computations in the language network: Characterising dynamic network properties using representational similarity analysis

    Directory of Open Access Journals (Sweden)

    Lorraine Komisarjevsky Tyler

    2013-05-01

    Full Text Available The core human capacity of syntactic analysis involves a left hemisphere network involving left inferior frontal gyrus (LIFG and posterior middle temporal gyrus (LMTG and the anatomical connections between them. Here we use MEG to determine the spatio-temporal properties of syntactic computations in this network. Listeners heard spoken sentences containing a local syntactic ambiguity (e.g. …landing planes…, at the offset of which they heard a disambiguating verb and decided whether it was an acceptable/unacceptable continuation of the sentence. We charted the time-course of processing and resolving syntactic ambiguity by measuring MEG responses from the onset of each word in the ambiguous phrase and the disambiguating word. We used representational similarity analysis (RSA to characterize syntactic information represented in the LIFG and LpMTG over time and to investigate their relationship to each other. Testing a variety of lexico-syntactic and ambiguity models against the MEG data, our results suggest early lexico-syntactic responses in the LpMTG and later effects of ambiguity in the LIFG, pointing to a clear differentiation in the functional roles of these two regions. Our results suggest the LpMTG represents and transmits lexical information to the LIFG, which responds to and resolves the ambiguity.

  8. Sentiment Analysis Based on Expanded Aspect and Polarity-Ambiguous Word Lexicon

    OpenAIRE

    Yanfang Cao; Pu Zhang; Anping Xiong

    2015-01-01

    This paper focuses on the task of disambiguating polarity-ambiguous words and the task is reduced to sentiment classification of aspects, which we refer to sentiment expectation instead of semantic orientation widely used in previous researches. Polarity-ambiguous words refer to words like” large, small, high, low ”, which pose a challenging task on sentiment analysis. In order to disambiguate polarity-ambiguous words, this paper constructs the aspect and polarity-ambiguous lexicon using a mu...

  9. Integer-ambiguity resolution in astronomy and geodesy

    CERN Document Server

    Lannes, André

    2013-01-01

    Recent theoretical developments in astronomical aperture synthesis have revealed the existence of integer-ambiguity problems. Those problems, which appear in the self-calibration procedures of radio imaging, have been shown to be similar to the nearest-lattice point (NLP) problems encountered in high-precision geodetic positioning, and in global navigation satellite systems. In this paper, we analyse the theoretical aspects of the matter and propose new methods for solving those NLP problems. The related optimization aspects concern both the preconditioning stage, and the discrete-search stage in which the integer ambiguities are finally fixed. Our algorithms, which are described in an explicit manner, can easily be implemented. They lead to substantial gains in the processing time of both stages. Their efficiency was shown via intensive numerical tests.

  10. Obstetricians' choice of cesarean delivery in ambiguous cases

    DEFF Research Database (Denmark)

    Fuglenes, Dorthe; Oian, Pål; Kristiansen, Ivar Sønbø

    2009-01-01

    . The perceived risk of complaints and malpractice litigation was a clear determinant of obstetricians' choice of cesarean in all of the clinical scenarios, whereas no impact was observed for risk attitude. CONCLUSION: Obstetricians' judgments about cesarean request in ambiguous clinical cases vary considerably......OBJECTIVE: The aim of this study was to test the hypothesis that obstetricians' choice of delivery method is influenced by their risk attitude and perceived risk of complaints and malpractice litigation. STUDY DESIGN: The choice of delivery method in ambiguous cases was studied in a nationwide...... survey of Norwegian obstetricians (n = 716; response rate, 71%) using clinical scenarios. The risk attitude was measured by 6 items from the Jackson Personality Inventory-Revised. RESULTS: The proportion of obstetricians consenting to the cesarean request varied both within and across the scenarios...

  11. Polysemy, syntactic constraints and reduction of ambiguity in controlled languages

    Directory of Open Access Journals (Sweden)

    Krzysztof Bogacki

    2015-01-01

    Full Text Available The article considers such peculiarities of the controlled languages as the choice of lexical units and constraints on their syntax. We review various difficulties that arise during the selection of forms we would like to put in the lexicon of a controlled language. We compare the index of multiple meanings of the words used to form the vocabulary of a controlled language before and after the lexical control and calculate the change in the ambiguity rate of sentences due to the elimination of polysemy. The words allowed in the lexicon of a controlled language usually have a high polysemy index in the standard language. This is evident especially as far as grammatical and non-technical words are concerned. In contrast, technical terms are much more often monosemic. Thus the observation of the “one token = one meaning” principle in the lexicon for the controlled language has a great effect on the decline of ambiguity.

  12. Punctuated equilibrium based on a locally ambiguous niche.

    Science.gov (United States)

    Gunji, Yukio-Pegio; Sakiyama, Tomoko; Murakami, Hisashi

    2014-09-01

    Punctuated equilibrium, recently regarded as the power law distribution of lifespan, is estimated with respect to self-organized criticality. Previous explanations were based on a global property, such as the selection of species depending on their fitness, however a particular entity defined through such global property cannot be relevant to the notion of "self". Here, we introduce local ambiguity of a niche with respect to function and define a function network by using two types of maps. Due to the local complex structure of the function network, motif and lateral connections, some species are easily replaced by others, and other species have long lives. Punctuated equilibrium can, therefore, be explained by local ambiguous interaction, which suggests the notion of self and supports the idea of self-organized criticality. PMID:24905426

  13. The Benefit of Ambiguity in Understanding Goals in Requirements Modelling

    DEFF Research Database (Denmark)

    Paay, Jeni; Pedell, Sonja; Sterling, Leon;

    2011-01-01

    This paper examines the benefit of ambiguity in describing goals in requirements modelling for the design of socio-technical systems using concepts from Agent-Oriented Software Engineering (AOSE) and ethnographic and cultural probe methods from Human Computer Interaction (HCI). The authors’ aim......-technological systems. Currently social needs are modelled as coordinative and collaborative goals; however the domestic space surfaces a range of purely communicative activities, which are not calculated to serve any external productive purpose (i.e., it is communication often for the sake of pleasure).The authors use...... ambiguity in the process of elicitation and analysis through the use of empirically informed quality goals attached to functional goals. The authors demonstrate the benefit of articulating a quality goal without turning it into a functional goal. Their study shows that quality goals kept at a high level...

  14. Ambiguities and Symmetry Relations in a Free Fermion Model

    CERN Document Server

    Battistel, O A

    1999-01-01

    We present a systematic study of one, two and three point functions of vector, axial-vector, scalar and pseudoscalar densities constructed in a free fermion model. The divergent content of the amplitudes are left in the form of (external momenta independent) 4-D integrals for which an appropriate regulating function is only implicitly assumed, and the integrals are not evaluated at any step of the calculation. The ambiguities and Symmetries Violations, in all cases, are shown to be associated with coefficients involving three relations between divergent integrals of the same degree of divergence. Setting these coefficients to zero is mandatory, e.g., for preserving gauge symmetry in QED. The implications for the ambiguities and symmetry violations are investigated. The results emerging from this alternative approach allow us to conclude that the traditional method used to establish the triangular anomalies could be questionable.

  15. Smelling directions: olfaction modulates ambiguous visual motion perception.

    Science.gov (United States)

    Kuang, Shenbing; Zhang, Tao

    2014-07-23

    Senses of smells are often accompanied by simultaneous visual sensations. Previous studies have documented enhanced olfactory performance with concurrent presence of congruent color- or shape- related visual cues, and facilitated visual object perception when congruent smells are simultaneously present. These visual object-olfaction interactions suggest the existences of couplings between the olfactory pathway and the visual ventral processing stream. However, it is not known if olfaction can modulate visual motion perception, a function that is related to the visual dorsal stream. We tested this possibility by examining the influence of olfactory cues on the perceptions of ambiguous visual motion signals. We showed that, after introducing an association between motion directions and olfactory cues, olfaction could indeed bias ambiguous visual motion perceptions. Our result that olfaction modulates visual motion processing adds to the current knowledge of cross-modal interactions and implies a possible functional linkage between the olfactory system and the visual dorsal pathway.

  16. Assignment of sex in neonates with ambiguous genitalia.

    Science.gov (United States)

    Reiner, W G

    1999-08-01

    Sex assignment in the newborn with ambiguous genitalia has been based on the adequacy of the phallus in the male, potential fertility in the female, and cosmetic appearance of the reconstructed genitalia. Recent data from both the neurosciences and from clinical research, however, casts doubt on the validity of such criteria for clinical decision making. Current knowledge suggests a need to shift away from the current clinical approach and to incorporate these new data into decisions based on a broader understanding of the etiology of gender identity. Recognition of the primacy of psychosocial and psychosexual developmental outcomes for children with ambiguous genitalia is lending direction to longitudinal outcomes research. New approaches to sex assignment have been suggested, and the paradigm for sex assignment in the newborn period is in transition.

  17. Interpretation bias in responses to ambiguous cues in pain patients.

    Science.gov (United States)

    Pincus, T; Pearce, S; McClelland, A; Farley, S; Vogel, S

    1994-05-01

    Pain patients and control subjects responses to ambiguous cues were compared in two separate investigations. In the first, pain patients, control subjects and physiotherapists were asked to produce a list of spontaneous associations to ambiguous cues (such as terminal and growth). To control for mood effects the experiment was repeated with three more groups: Pain patients, osteopaths and a control group. Measures of anxiety and depression were incorporated in the analysis. Results indicate that pain patients systematically produce more pain related associations than the other groups, and that this effect is independent of anxiety and depression levels. The discussion concentrates on the implications of these findings both for the theory of pain processing and for clinical interventions.

  18. Acuity of mental representations of pitch.

    Science.gov (United States)

    Janata, Petr

    2012-04-01

    Singing in one's mind or forming expectations about upcoming notes both require that mental images of one or more pitches will be generated. As with other musical abilities, the acuity with which such images are formed might be expected to vary across individuals and may depend on musical training. Results from several behavioral tasks involving intonation judgments indicate that multiple memory systems contribute to the formation of accurate mental images for pitch, and that the functionality of each is affected by musical training. Electrophysiological measures indicate that the ability to form accurate mental images is associated with greater engagement of auditory areas and associated error-detection circuitry when listeners imagine ascending scales and make intonation judgments about target notes. A view of auditory mental images is espoused in which unified mental image representations are distributed across multiple brain areas. Each brain area helps shape the acuity of the unified representation based on current behavioral demands and past experience. PMID:22524362

  19. HEISENBERG'S INEQUALITY AND LOGARITHMIC HEISENBERG'S INEQUALITY FOR AMBIGUITY FUNCTION

    Institute of Scientific and Technical Information of China (English)

    Tian Guji

    2000-01-01

    In this article we discuss the relation between Heisenberg's inequality and logarithmic Heisenberg's (entropy) inequality for ambiguity function. After building up a Heisenberg's inequality, we obtain a connection of variance with entropy by variational method. Using classical Taylor's expansion, we prove that the equality in Heisenberg's inequality holds if and only if the entropy of 2k - 1 order is equal to (2k - 1)!.

  20. Effects of pitch accents in attachment ambiguity resolution

    OpenAIRE

    Lee, Eun-Kyung; Watson, Duane G.

    2011-01-01

    Previous work has found that listeners prefer to attach ambiguous syntactic constituents to nouns produced with a pitch accent (Schafer et al., 1996). This study examines what factors underlie previously established accent attachment effects by testing whether these effects are driven by a preference to attach syntactic constituents to new or important information (the Syntax Hypothesis) or whether there is a bias to respond to post-sentence probe questions with an accented word (the Salience...

  1. Another Kind of Ambiguous Loss: Seventh-Day Adventist Women in Mixed-Orientation Marriages

    Science.gov (United States)

    Hernandez, Barbara C.; Wilson, Colwick M.

    2007-01-01

    Narratives of five Seventh-day Adventist heterosexual women whose mixed-orientation marriages ended were analyzed through the lens of ambiguous loss. Thematic coding identified a wave-like process of changing emotional foci that emerged from their experience during marital dissolution. Elements of ambiguous loss included boundary ambiguity,…

  2. Inherent ambiguities in the determination of phase-shifts

    International Nuclear Information System (INIS)

    The observables in an elastic scattering process are unchanged if all the scattering amplitudes are multiplied by the same angle-dependent phase. The non-spin-flip and spin-flip amplitudes remain unchanged by the substitution: g(cos theta)→g(cos theta)exp[i phi(cos theta)] and h(cos theta)→h(cos theta)exp[i phi(cos theta)]. Unless some extra and hoc assumption is made, there is a continuum ambiguity, which has been explored some time ago, with specific models for the phase phi by members of the Birmingham group. In the ordinary quantum mechanics of scattering, one writes a wave-function asymptotically as psi(r-) approximately esup(ikr costheta)+f(cos theta)esup(ikr)/r where f is the scattering amplitude. The ambiguity which is a change in the phase of the scattering amplitude, and thus of the scattered part of the wavefunction, but with no change of the first term in (the unscattered plane wave coming along the z-axis is discussed in detail. Preliminary results in the energy-range 1550-1750 MeV cm and their implications are given. Argand plots of ambiguities at various energies are presented. (K.B.)

  3. Perceptual learning of a talker resolves lexical ambiguity

    Science.gov (United States)

    Piorkowski, Rebecca L.; Badecker, William

    2005-09-01

    Recent evidence [Allen and Miller, J. Acoust. Soc. Am. 115, 3171 (2004)] suggests that listeners are sensitive to talker-specific acoustic-phonetic properties. The present study examines whether experience with a particular talker's realization of place of articulation can eliminate the ambiguity that arises when a word like ``hen'' assimilates in place of articulation to ``hem'' in a labial context (hen best). Using a cross-modal priming paradigm, the priming effect of words that assimilate to other words was measured in two conditions. In the first condition, listeners heard examples of the talker's assimilation style in the form of words that assimilate to nonwords in a labial context (green beer) before the critical trials were heard. In the second condition, listeners did not hear any examples of the talker's assimilation style before the critical trials were heard. Evidence will be presented showing that, without previous experience with the talker's assimilation style, words that assimilate to other words create a lexical ambiguity for the listener. Additionally, evidence will be presented showing that experience with the talker's assimilation style eliminates this lexical ambiguity and allows the listener to perceive the talker's intended lexical form.

  4. Right semantic modulation of early MEG components during ambiguity resolution.

    Science.gov (United States)

    Harpaz, Yuval; Lavidor, Michal; Goldstein, Abraham

    2013-11-15

    The time-line of lexical ambiguity resolution in bilateral neuronal networks was investigated using magnetoencephalography (MEG) in a semantic decision task. Dominant and subordinate associations of ambiguous words are considered to be processed in the left and right hemispheres, respectively. In the experiment, ambiguous words were followed by dominant or subordinate associations (manipulated between blocks) or by unrelated target words, and participants (N=25) decided whether the words in each pair were related or not. Subordinate meaning blocks elicited greater changes in the magnetic fields relative to dominant ones over the right, but not the left hemisphere (LH) at 150-235 ms from target onset, a time window corresponding to the M/N170 M/EEG component. Beamforming analysis localized the differential right hemisphere (RH) activity at the perisylvian area, including the homologue regions of Broca's and Wernicke's. At a later stage (235-390 ms) there was no significant difference between the two meaning conditions. We suggest that the RH language regions assist the LH in integrating subordinate disambiguating clues to preceding context during the M170 time window. PMID:23707585

  5. Semantics and ambiguity of stochastic RNA family models.

    Science.gov (United States)

    Giegerich, Robert; Höner zu Siederdissen, Christian

    2011-01-01

    Stochastic models, such as hidden Markov models or stochastic context-free grammars (SCFGs) can fail to return the correct, maximum likelihood solution in the case of semantic ambiguity. This problem arises when the algorithm implementing the model inspects the same solution in different guises. It is a difficult problem in the sense that proving semantic nonambiguity has been shown to be algorithmically undecidable, while compensating for it (by coalescing scores of equivalent solutions) has been shown to be NP-hard. For stochastic context-free grammars modeling RNA secondary structure, it has been shown that the distortion of results can be quite severe. Much less is known about the case when stochastic context-free grammars model the matching of a query sequence to an implicit consensus structure for an RNA family. We find that three different, meaningful semantics can be associated with the matching of a query against the model--a structural, an alignment, and a trace semantics. Rfam models correctly implement the alignment semantics, and are ambiguous with respect to the other two semantics, which are more abstract. We show how provably correct models can be generated for the trace semantics. For approaches, where such a proof is not possible, we present an automated pipeline to check post factum for ambiguity of the generated models. We propose that both the structure and the trace semantics are worth-while concepts for further study, possibly better suited to capture remotely related family members.

  6. Representational similarity analysis - connecting the branches of systems neuroscience

    Directory of Open Access Journals (Sweden)

    2008-11-01

    Full Text Available A fundamental challenge for systems neuroscience is to quantitatively relate its three major branches of research: brain-activity measurement, behavioral measurement, and computational modeling. Using measured brain-activity patterns to evaluate computational network models is complicated by the need to define the correspondency between the units of the model and the channels of the brain-activity data, e.g. single-cell recordings or voxels from functional magnetic resonance imaging (fMRI. Similar correspondency problems complicate relating activity patterns between different modalities of brain-activity measurement, and between subjects and species. In order to bridge these divides, we suggest abstracting from the activity patterns themselves and computing representational dissimilarity matrices, which characterize the information carried by a given representation in a brain or model. We propose a new experimental and data-analytical framework called representational similarity analysis (RSA, in which multi-channel measures of neural activity are quantitatively related to each other and to computational theory and behavior by comparing representational dissimilarity matrices. We demonstrate RSA by relating representations of visual objects as measured with fMRI to computational models spanning a wide range of complexities. We argue that these ideas, which have deep roots in psychology and neuroscience, will allow the integrated quantitative analysis of data from all three branches, thus contributing to a more unified systems neuroscience.

  7. Neural response to modulating the probability that actions of self or other result in auditory tones: A parametric fMRI study into causal ambiguity.

    Science.gov (United States)

    de Bézenac, Christophe E; Sluming, Vanessa; Gouws, André; Corcoran, Rhiannon

    2016-09-01

    In normal circumstances we can easily distinguish between changes to the external world brought about by our own actions from those with external causes. However, in certain contexts our sense of ownership and agency over acts is not so clear. Neuroimaging studies have implicated a number of regions in the sense of agency, some of which have been shown to vary continuously with action-outcome discordance. However, little is known about dynamic, ambiguous contexts characterised by a lack of information for self-other differentiation, yet such ambiguous states are important in relation to symptoms and levels of consciousness that characterise certain mental health conditions. With a block-design fMRI paradigm, we investigated neural responses to changes in the probability that a participant's irregular finger taps over 12s would result in auditory tones as opposed to tones generated by 'another's finger taps'. The main findings were that misattribution increased in ambiguous conditions where the probability of a tone belonging to self and other was equal. Task-sensitive brain regions, previously identified in self-agency, motor cognition, and ambiguity processing, showed a quadratic response to our self-to-other manipulation, with particular sensitivity to self-control. Task performance (low error and bias) was related to attenuated response in ambiguous conditions while increased response in regions associated with the default mode network was associated with greater overall error and bias towards other. These findings suggest that causal ambiguity as it occurs over time is a prominent feature in sense of agency, one that may eventually contribute to a more comprehensive understanding of positive symptoms of psychosis.

  8. Animating Brains

    Science.gov (United States)

    Borck, Cornelius

    2016-01-01

    A recent paper famously accused the rising field of social neuroscience of using faulty statistics under the catchy title ‘Voodoo Correlations in Social Neuroscience’. This Special Issue invites us to take this claim as the starting point for a cross-cultural analysis: in which meaningful ways can recent research in the burgeoning field of functional imaging be described as, contrasted with, or simply compared to animistic practices? And what light does such a reading shed on the dynamics and effectiveness of a century of brain research into higher mental functions? Reviewing the heated debate from 2009 around recent trends in neuroimaging as a possible candidate for current instances of ‘soul catching’, the paper will then compare these forms of primarily image-based brain research with older regimes, revolving around the deciphering of the brain’s electrical activity. How has the move from a decoding paradigm to a representational regime affected the conceptualisation of self, psyche, mind and soul (if there still is such an entity)? And in what ways does modern technoscience provide new tools for animating brains? PMID:27292322

  9. In defense of abstract conceptual representations.

    Science.gov (United States)

    Binder, Jeffrey R

    2016-08-01

    An extensive program of research in the past 2 decades has focused on the role of modal sensory, motor, and affective brain systems in storing and retrieving concept knowledge. This focus has led in some circles to an underestimation of the need for more abstract, supramodal conceptual representations in semantic cognition. Evidence for supramodal processing comes from neuroimaging work documenting a large, well-defined cortical network that responds to meaningful stimuli regardless of modal content. The nodes in this network correspond to high-level "convergence zones" that receive broadly crossmodal input and presumably process crossmodal conjunctions. It is proposed that highly conjunctive representations are needed for several critical functions, including capturing conceptual similarity structure, enabling thematic associative relationships independent of conceptual similarity, and providing efficient "chunking" of concept representations for a range of higher order tasks that require concepts to be configured as situations. These hypothesized functions account for a wide range of neuroimaging results showing modulation of the supramodal convergence zone network by associative strength, lexicality, familiarity, imageability, frequency, and semantic compositionality. The evidence supports a hierarchical model of knowledge representation in which modal systems provide a mechanism for concept acquisition and serve to ground individual concepts in external reality, whereas broadly conjunctive, supramodal representations play an equally important role in concept association and situation knowledge. PMID:27294428

  10. Hyperfinite Representation of Distributions

    Indian Academy of Sciences (India)

    J Sousa Pinto; R F Hoskins

    2000-11-01

    Hyperfinite representation of distributions is studied following the method introduced by Kinoshita [2, 3], although we use a different approach much in the vein of [4]. Products and Fourier transforms of representatives of distributions are also analysed.

  11. Suppressing azimuth ambiguity in spaceborne SAR images based on compressed sensing

    Institute of Scientific and Technical Information of China (English)

    YU Ze; LIU Min

    2012-01-01

    In spaceborne synthetic aperture radar,undersampling at the rate of the pulse repetition frequency causes azimuth ambiguity,which induces ghost into the images.This paper introduces compressed sensing for azimuth ambiguity suppression and presents two novel methods from the perspectives of system design and image formation,known as azimuth random sampling and ambiguity separation,respectively.The first method makes the imaging results for the ambiguity zones as disperse as possible while ensuring that the imaging results for the main scene are affected as little as possible.The second method separates the ambiguity signals from the echoes and achieves imaging results without the ambiguity effect.Simulation results show that the two methods can reduce the ambiguity levels by about 16 dB and 99.37%,respectively.

  12. Mapping brain function to brain anatomy

    International Nuclear Information System (INIS)

    In Imaging the human brain, MRI is commonly used to reveal anatomical structure, while PET is used to reveal tissue function. This paper presents a protocol for correlating data between these two imaging modalities; this correlation can provide in vivo regional measurements of brain function which are essential to our understanding of the human brain. The authors propose a general protocol to standardize the acquisition and analysis of functional image data. First, MR and PET images are collected to form three-dimensional volumes of structural and functional image data. Second, these volumes of image data are corrected for distortions inherent in each imaging modality. Third, the image volumes are correlated to provide correctly aligned structural and functional images. The functional images are then mapped onto the structural images in both two-dimensional and three-dimensional representations. Finally, morphometric techniques can be used to provide statistical measures of the structure and function of the human brain

  13. Embedded data representations

    DEFF Research Database (Denmark)

    Willett, W.; Jansen, Yvonne; Dragicevic, P.

    2016-01-01

    We introduce embedded data representations, the use of visual and physical representations of data that are deeply integrated with the physical spaces, objects, and entities to which the data refers. Technologies like lightweight wireless displays, mixed reality hardware, and autonomous vehicles ......-situated, situated, and embedded data displays, including both visualizations and physicalizations. Based on our observations, we identify a variety of design challenges for embedded data representation, and suggest opportunities for future research and applications.......We introduce embedded data representations, the use of visual and physical representations of data that are deeply integrated with the physical spaces, objects, and entities to which the data refers. Technologies like lightweight wireless displays, mixed reality hardware, and autonomous vehicles...... are making it increasingly easier to display data in-context. While researchers and artists have already begun to create embedded data representations, the benefits, trade-offs, and even the language necessary to describe and compare these approaches remain unexplored. In this paper, we formalize the notion...

  14. Dressed skeleton expansion and the coupling scale ambiguity problem

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Hung Jung

    1992-09-01

    Perturbative expansions in quantum field theories are usually expressed in powers of a coupling constant. In principle, the infinite sum of the expansion series is independent of the renormalization scale of the coupling constant. In practice, there is a remnant dependence of the truncated series on the renormalization scale. This scale ambiguity can severely restrict the predictive power of theoretical calculations. The dressed skeleton expansion is developed as a calculational method which avoids the coupling scale ambiguity problem. In this method, physical quantities are expressed as functional expansions in terms of a coupling vertex function. The arguments of the vertex function are given by the physical momenta of each process. These physical momenta effectively replace the unspecified renormalization scale and eliminate the ambiguity problem. This method is applied to various field theoretical models and its main features and limitations are explored. For quantum chromodynamics, an expression for the running coupling constant of the three-gluon vertex is obtained. The effective coupling scale of this vertex is shown to be essentially given by {mu}{sup 2} {approximately} Q{sub min}{sup 2}Q{sub med}{sup 2}/Q{sub max}{sup 2} where Q{sub min}{sup 2}Q{sub med}{sup 2}/Q{sub max}{sup 2} are respectively the smallest, the next-to-smallest and the largest scale among the three gluon virtualities. This functional form suggests that the three-gluon vertex becomes non-perturbative at asymmetric momentum configurations. Implications for four-jet physics is discussed.

  15. Reconsideration of Ambiguities in Quad-Pol SAR

    OpenAIRE

    Villano, Michelangelo; Krieger, Gerhard; Moreira, Alberto

    2016-01-01

    Merging the complex signals available from both cross-polarized (cross-pol) channels of a quad-polarimetric (quad-pol) synthetic aperture radar (SAR) may lead not only to a 3-dB gain in the signal-to-noise ratio (SNR), but also to a remarkable improvement in the azimuth and range ambiguity-to-signal ratios (AASR, RASR) of cross-pol data, especially if azimuth phase coding is employed. Staggered SAR operation is also addressed, for which a novel azimuth phase code is proposed. Range ambiguitie...

  16. On the Problem of Ambiguity of Electromagnetic Potential

    CERN Document Server

    Gritsunov, A V

    2013-01-01

    In the self-sufficient potential formalism, treating all electromagnetic phenomena as natural or forced oscillations of some distributed electromagnetic oscillating system (Minkowski space-time), the electromagnetic potential must be considered as some relative measure describing deviation of the system from its "undisturbed" state (when both natural and forced oscillations are absent). Therefore, there is no ambiguity in the gauge of one: all components of the potential four-vector are asymptotically verging towards zero while the distance from all free charges and currents enlarges. Such interpretation turns the electromagnetic potential into a physically real value.

  17. Sibling jealousy and aesthetic ambiguity in Austen's Pride and Prejudice.

    Science.gov (United States)

    Hanly, Margaret Ann Fitzpatrick

    2009-04-01

    Jane Austen's most popular novel, Pride and Prejudice (1813), illuminates and is illuminated by psychoanalytic aesthetics. When Austen dramatizes unconscious oedipal/sibling rivalries, irony acts as a type of aesthetic ambiguity (E. Kris 1952). A psychoanalytic perspective shows that Austen uses a grammar of negatives (negation, denial, minimization) to achieve the dual meanings of irony, engaging the reader's unconscious instinctual satisfactions, while at the same time protecting the reader from unpleasant affects. Austen's plot, which portrays regressions driven by sibling jealousy, reveals that a new tolerance of remorse and depression in her heroine and hero leads to psychic growth.

  18. SAR antenna design for ambiguity and multipath suppression

    DEFF Research Database (Denmark)

    Christensen, Erik Lintz; Dich, Mikael

    1993-01-01

    A high resolution airborne synthetic aperture radar (SAR) has been developed at the Electromagnetics Institute (EMI) for remote sensing applications. The paper considers the radiation of antennas for a SAR system from a systems perspective. The basic specifications of an idealised antenna...... are obtained from the required swath and the azimuth footprint needed for the SAR processing. The radiation from a real antenna causes unwanted signal returns that lead to intensity variations (multipath) and ghost echoes (ambiguity). Additional specifications are deduced by considering these signals...

  19. New Ambiguity in Probing C P Violation in Neutrino Oscillations

    Science.gov (United States)

    Miranda, O. G.; Tórtola, M.; Valle, J. W. F.

    2016-08-01

    If neutrinos get mass via the seesaw mechanism the mixing matrix describing neutrino oscillations can be effectively nonunitary. We show that in this case the neutrino appearance probabilities involve a new C P phase ϕ associated with nonunitarity. This leads to an ambiguity in extracting the "standard" three-neutrino phase δC P, which can survive even after neutrino and antineutrino channels are combined. Its existence should be taken into account in the planning of any oscillation experiment aiming at a robust measurement of δC P.

  20. New ambiguity in probing CP violation in neutrino oscillations

    CERN Document Server

    Miranda, O G; Valle, J W F

    2016-01-01

    If neutrinos get mass a la seesaw the mixing matrix describing neutrino oscillations can be effectively non-unitary. We show that in this case the neutrino appearance probabilities involve a new CP phase, phi, associated to non-unitarity. This leads to an ambiguity in extracting the "standard" three--neutrino phase delta_CP, which can survive even after neutrino and antineutrino channels are combined. Its existence should be taken into account in the planning of any oscillation experiment aiming at a robust measurement of delta_CP.

  1. Optimal ambiguity functions and Weil's exponential sum bound

    OpenAIRE

    Benedetto, John J.; Benedetto, Robert L.; Woodworth, Joseph T.

    2011-01-01

    Complex-valued periodic sequences, u, constructed by Goran Bjorck, are analyzed with regard to the behavior of their discrete periodic narrow-band ambiguity functions A_p(u). The Bjorck sequences, which are defined on Z/pZ for p>2 prime, are unimodular and have zero autocorrelation on (Z/pZ)\\{0}. These two properties give rise to the acronym, CAZAC, to refer to constant amplitude zero autocorrelation sequences. The bound proven is |A_p(u)| \\leq 2/\\sqrt{p} + 4/p outside of (0,0), and this is o...

  2. Removing grammar ambiguity of word forms by statistical methods

    Directory of Open Access Journals (Sweden)

    Ganna Karnaukh

    2014-09-01

    Full Text Available Removing grammar ambiguity of word forms by statistical methodsResearch is devoted to the study of behaviour of linguistic processor at simultaneous application of software supporting functions (taking into account the characteristics of the writing word forms (capital / small letters, punctuation marks in trigrams and location of trigrams within a sentence. The article analyses qualitative quantitative characteristics of the results removing grammatical homonyms of word forms using statistical methods in compliance with requirements. The research is based on the texts of normative legal document.

  3. Psychoanalytic and musical ambiguity: the tritone in gee, officer krupke.

    Science.gov (United States)

    Jaffee Nagel, Julie

    2010-02-01

    The poignant and timeless Broadway musical West Side Story is viewed from the standpoint of taking musical forms as psychoanalytic data. The musical configuration of notes called the tritone (or diabolus in musica) is taken as a sonic metaphor expressing ambiguity both in musical vocabulary and in mental life. The tritone, which historically and harmonically represents instability, is heard throughout the score and emphasizes the intrapsychic, interpersonal, and social dramas that unfold within and between the two gangs in West Side Story. Particular emphasis is given to the comic but exceedingly sober song Gee, Officer Krupke. Bernstein's sensitivity to the ambiguity and tension inherent in the tritone in West Side Story is conceptualized as an intersection of music theory and theories of mind; this perspective holds implications for clinical practice and transports psychoanalytic concepts from the couch to the Broadway stage and into the community to address the complexities of love, hate, aggression, prejudice, and violence. Ultimately, West Side Story cross-pollinates music and theater, as well as music and psychoanalytic concepts. PMID:20234007

  4. A Computational Model of Syntactic Processing Ambiguity Resolution from Interpretation

    CERN Document Server

    Niv, M

    1994-01-01

    Syntactic ambiguity abounds in natural language, yet humans have no difficulty coping with it. In fact, the process of ambiguity resolution is almost always unconscious. But it is not infallible, however, as example 1 demonstrates. 1. The horse raced past the barn fell. This sentence is perfectly grammatical, as is evident when it appears in the following context: 2. Two horses were being shown off to a prospective buyer. One was raced past a meadow. and the other was raced past a barn. ... Grammatical yet unprocessable sentences such as 1 are called `garden-path sentences.' Their existence provides an opportunity to investigate the human sentence processing mechanism by studying how and when it fails. The aim of this thesis is to construct a computational model of language understanding which can predict processing difficulty. The data to be modeled are known examples of garden path and non-garden path sentences, and other results from psycholinguistics. It is widely believed that there are two distinct loci...

  5. Psychoanalytic and musical ambiguity: the tritone in gee, officer krupke.

    Science.gov (United States)

    Jaffee Nagel, Julie

    2010-02-01

    The poignant and timeless Broadway musical West Side Story is viewed from the standpoint of taking musical forms as psychoanalytic data. The musical configuration of notes called the tritone (or diabolus in musica) is taken as a sonic metaphor expressing ambiguity both in musical vocabulary and in mental life. The tritone, which historically and harmonically represents instability, is heard throughout the score and emphasizes the intrapsychic, interpersonal, and social dramas that unfold within and between the two gangs in West Side Story. Particular emphasis is given to the comic but exceedingly sober song Gee, Officer Krupke. Bernstein's sensitivity to the ambiguity and tension inherent in the tritone in West Side Story is conceptualized as an intersection of music theory and theories of mind; this perspective holds implications for clinical practice and transports psychoanalytic concepts from the couch to the Broadway stage and into the community to address the complexities of love, hate, aggression, prejudice, and violence. Ultimately, West Side Story cross-pollinates music and theater, as well as music and psychoanalytic concepts.

  6. Ambivalence and Ambiguity in The Autobiography of Miss Jane Pittman

    Directory of Open Access Journals (Sweden)

    Monica Michlin

    2006-05-01

    Full Text Available This close reading of the text highlights how Miss Jane, in her double role as protagonist and narrator, shows considerable ambivalence towards friend and foe alike, with the result that the apparently transparent ideological meaning of entire episodes is blurred by what some critics have merely put down to “conservatism.” I examine Miss Jane’s almost constant suppression of emotion, and frequent displays of ambivalence towards other black people; her ambiguous relationship to oppressive, but familiar whites like Albert Cluveau or Robert Samson; and her conflicted relation to black heroes and heroics. Is the leading character a variation on the “mammy” who has internalized racist figures of speech, and uses contradictory images that undermine black heroics and validate white oppression? Or is Gaines’s point to undo the “retrick” of heroics and of alienation alike, and, against of backdrop of constant, ordinary destruction of black lives, to cast the adult Miss Jane as a Brer Rabbit-like figure, for whom survival and resistance are both dialectically connected and opposed? Is there a contradiction between her “progress” towards resistance shown in the last section, and her metadiscursive comments in the present, and does her literally walking out of her own story give a conclusive meaning to her narrative, or does it point to the author’s not having been able to resolve the ambivalence and ambiguities within the text?

  7. Resolution of ambiguities in cartoons as an illustration of the role of pragmatics in natural language understanding by computers

    Energy Technology Data Exchange (ETDEWEB)

    Mazlack, L.J.; Paz, N.M.

    1983-01-01

    Newspaper cartoons can graphically display the result of ambiguity in human speech; the result can be unexpected and funny. Likewise, computer analysis of natural language statements also needs to successfully resolve ambiguous situations. Computer techniques already developed use restricted world knowledge in resolving ambiguous language use. This paper illustrates how these techniques can be used in resolving ambiguous situations arising in cartoons. 8 references.

  8. Brain Basics

    Medline Plus

    Full Text Available ... News About Us Home > Health & Education > Educational Resources Brain Basics Introduction The Growing Brain The Working Brain ... to mental disorders, such as depression. The Growing Brain Inside the Brain: Neurons & Neural Circuits Neurons are ...

  9. Brain Basics

    Science.gov (United States)

    ... News About Us Home > Health & Education > Educational Resources Brain Basics Introduction The Growing Brain The Working Brain ... to mental disorders, such as depression. The Growing Brain Inside the Brain: Neurons & Neural Circuits Neurons are ...

  10. Brain Basics

    Medline Plus

    Full Text Available ... Brain Basics provides information on how the brain works, how mental illnesses are disorders of the brain, ... learning more about how the brain grows and works in healthy people, and how normal brain development ...

  11. Representation Discovery using Harmonic Analysis

    CERN Document Server

    Mahadevan, Sridhar

    2008-01-01

    Representations are at the heart of artificial intelligence (AI). This book is devoted to the problem of representation discovery: how can an intelligent system construct representations from its experience? Representation discovery re-parameterizes the state space - prior to the application of information retrieval, machine learning, or optimization techniques - facilitating later inference processes by constructing new task-specific bases adapted to the state space geometry. This book presents a general approach to representation discovery using the framework of harmonic analysis, in particu

  12. Understanding representations in design

    DEFF Research Database (Denmark)

    Bødker, Susanne

    1998-01-01

    Representing computer applications and their use is an important aspect of design. In various ways, designers need to externalize design proposals and present them to other designers, users, or managers. This article deals with understanding design representations and the work they do in design....... The article is based on a series of theoretical concepts coming out of studies of scientific and other work practices and on practical experiences from design of computer applications. The article presents alternatives to the ideas that design representations are mappings of present or future work...... regarding use and design. The article proposes that abstraction, elevating the representation from the situation, is not the only way to do this, and it proposes alternatives....

  13. Memetics of representation

    Directory of Open Access Journals (Sweden)

    Roberto De Rubertis

    2012-06-01

    Full Text Available This article will discuss about the physiological genesis of representation and then it will illustrate the developments, especially in evolutionary perspective, and it will show how these are mainly a result of accidental circumstances, rather than of deliberate intention of improvement. In particular, it will be argue that the representation has behaved like a meme that has arrived to its own progressive evolution coming into symbiosis with the different cultures in which it has spread, and using in this activity human work “unconsciously”. Finally it will be shown how in this action the geometry is an element key, linked to representation both to construct images using graphics operations and to erect buildings using concrete operations.

  14. Scientific Representation and Realism

    Directory of Open Access Journals (Sweden)

    Michel Ghins

    2011-12-01

    Full Text Available After a brief presentation of what I take to be the representational démarche in science, I stress the fundamental role of true judgements in model construction. The success and correctness of a representation rests on the truth of judgements which attribute properties to real targeted entities, called “ontic judgements”. I then present what van Fraassen calls “the Loss of Reality objection”. After criticizing his dissolution of the objection, I offer an alternative way of answering the Loss of Reality objection by showing that the contact of our models with reality is grounded on the truth of ontic judgements. I conclude by examining.

  15. Additive and polynomial representations

    CERN Document Server

    Krantz, David H; Suppes, Patrick

    1971-01-01

    Additive and Polynomial Representations deals with major representation theorems in which the qualitative structure is reflected as some polynomial function of one or more numerical functions defined on the basic entities. Examples are additive expressions of a single measure (such as the probability of disjoint events being the sum of their probabilities), and additive expressions of two measures (such as the logarithm of momentum being the sum of log mass and log velocity terms). The book describes the three basic procedures of fundamental measurement as the mathematical pivot, as the utiliz

  16. Sentiment Analysis Based on Expanded Aspect and Polarity-Ambiguous Word Lexicon

    Directory of Open Access Journals (Sweden)

    Yanfang Cao

    2015-02-01

    Full Text Available This paper focuses on the task of disambiguating polarity-ambiguous words and the task is reduced to sentiment classification of aspects, which we refer to sentiment expectation instead of semantic orientation widely used in previous researches. Polarity-ambiguous words refer to words like” large, small, high, low ”, which pose a challenging task on sentiment analysis. In order to disambiguate polarity-ambiguous words, this paper constructs the aspect and polarity-ambiguous lexicon using a mutual bootstrapping algorithm. So the sentiment of polarity-ambiguous words in context can be decided collaboratively by the sentiment expectation of the aspects and polarity-ambiguous words’ prior polarity.At sentence level, experiments show that our method is effective in sentiment analysis.

  17. On ambiguity. Its locus in the architecture of Language and its origin in efficient communication

    CERN Document Server

    Fortuny, Jordi

    2011-01-01

    Ambiguity is an indisputable and ubiquitous feature of linguistic products. In this article we investigate both the locus of ambiguity in the architecture of Language and the origin of ambiguity in natural communication systems. We locate ambiguity at the \\textit{externalization branch} of Language and we study the emergence of ambiguity in communication through the concept of logical irreversibility and within the framework of Shannon's information theory. This leads us to a precise and general expression of the intuition behind Zipf's vocabulary balance in terms of a symmetry equation between the complexities of the coding and the decoding processes that imposes an unavoidable amount of logical uncertainty in natural communication. Accordingly, the emergence of irreversible computations is required if the complexities of the coding and the decoding processes are balanced in a symmetric scenario, which means that the emergence of ambiguous codes is a necessary condition for natural communication to succeed.

  18. Knowledge Representation in pAninI Framework Using Neural Network Model

    Directory of Open Access Journals (Sweden)

    Smita Selot

    2013-07-01

    Full Text Available Knowledge representation is base for expressing semantic content of input in intelligent information retrieval systems. Identification of semantic requires processing of input language at various levels. To make system understand text or speech is a challenging task as it involves extracting semantics of the language which itself is a complex problem. At the same time languages posses with multiple ambiguities and uncertainty which needs to be resolved at various phases of language processing. Level of understandability depends upon the grammar, syntactic and semantic representation of the language and methods employed for these analysis. Processing depends on the type of language, grammar of the language, ambiguities present and size of corpus available. Order free language posses different features as compared to rigid order language. Most of the Indian languages are order free; hence mechanism for such language needs to be formulated. One of the ancient Indian Sanskrit grammarians, pAninI has defined grammar of Sanskrit language in such a way that it is suitable for computational analysis. Six main semantic class identified under this theory is a baseline model for knowledge representation. This paper exploits the features of the language, applicability of rules and resolving ambiguities using neural network model. A hybrid model incorporating the features of rules based and neural network the is designed and implemented for pAninI based semantic analysis, generating case frames as output.

  19. Image accuracy and representational enhancement through low-level, multi-sensor integration techniques

    Energy Technology Data Exchange (ETDEWEB)

    Baker, J.E.

    1994-09-01

    Multi-Sensor Integration (MSI) is the combining of data and information from more than one source in order to generate a more reliable and consistent representation of the environment. The need for MSI derives largely from basic ambiguities inherent in our current sensor imaging technologies. These ambiguities exist as long as the mapping from reality to image is not 1-to-1. That is, if different {open_quotes}realities{close_quotes} lead to identical images, a single image cannot reveal the particular reality which was the truth. MSI techniques attempt to resolve some of these ambiguities by appropriately coupling complementary images to eliminate possible inverse mappings. What constitutes the best MSI technique is dependent on the given application domain, available sensors, and task requirements. MSI techniques can be divided into three categories based on the relative information content of the original images with that of the desired representation: (1) {open_quotes}detail enhancement,{close_quotes} wherein the relative information content of the original images is less rich than the desired representation; (2) {open_quotes}data enhancement,{close_quotes} wherein the MSI techniques are concerned with improving the accuracy of the data rather than either increasing or decreasing the level of detail; and (3) {open_quotes}conceptual enhancement,{close_quotes} wherein the image contains more detail than is desired, making it difficult to easily recognize objects of interest. In conceptual enhancement one must group pixels corresponding to the same conceptual object and thereby reduce the level of extraneous detail.

  20. Multisensory body representation in autoimmune diseases.

    Science.gov (United States)

    Finotti, Gianluca; Costantini, Marcello

    2016-02-12

    Body representation has been linked to the processing and integration of multisensory signals. An outstanding example of the pivotal role played by multisensory mechanisms in body representation is the Rubber Hand Illusion (RHI). In this paradigm, multisensory stimulation induces a sense of ownership over a fake limb. Previous work has shown high interindividual differences in the susceptibility to the RHI. The origin of this variability remains largely unknown. Given the tight and bidirectional communication between the brain and the immune system, we predicted that the origin of this variability could be traced, in part, to the immune system's functioning, which is altered by several clinical conditions, including Coeliac Disease (CD). Consistent with this prediction, we found that the Rubber Hand Illusion is stronger in CD patients as compared to healthy controls. We propose a biochemical mechanism accounting for the dependency of multisensory body representation upon the Immune system. Our finding has direct implications for a range of neurological, psychiatric and immunological conditions where alterations of multisensory integration, body representation and dysfunction of the immune system co-exist.

  1. SAR Cross-Ambiguities in SAOCOM-CS Large Baseline Bistatic Configuration

    OpenAIRE

    Bordoni, Federica; Rodriguez-Cassola, Marc; Younis, Marwan; Prats-Iraola, Pau; Lopez-dekker, Paco; Krieger, Gerhard

    2016-01-01

    The evaluation of the ambiguous signal level, the Ambiguity-to-Signal Ratio (ASR), plays a key role in the Synthetic Aperture Radar (SAR) design and performance prediction. In conventional SAR acquisition scenarios, the computation of the ASR is based on the evaluation of the range and azimuth ambiguous contributes. Though appealing for its simplicity, this approach could be inaccurate in case of complex SAR acquisition geometries. In this paper we focus on the ASR performance of the SAOCOM-...

  2. Achieving collaboration with diverse stakeholders - the role of strategic ambiguity in CSR communication

    OpenAIRE

    Scandelius, C; Cohen, G.

    2016-01-01

    This paper seeks to explore how the concept of strategic ambiguity could have a role in CSR communication to stimulate collaboration with diverse stakeholders. The research is undertaken through a multiple case study in the food and drink value chain in Western Europe. The findings suggest a number of drivers for strategic ambiguity and connect these to active versus passive stakeholder response. Further it advises how strategic ambiguity may be applied in CSR communication both across the wi...

  3. Lexical ambiguity resolution for Turkish in direct transfer machine translation models

    OpenAIRE

    Tantuğ, A. Cüneyd; Tantug, A. Cuneyd; Oflazer, Kemal; Adalı, Eşref; Adali, Esref

    2006-01-01

    This paper presents a statistical lexical ambiguity resolution method in direct transfer machine translation models in which the target language is Turkish. Since direct transfer MT models do not have full syntactic information, most of the lexical ambiguity resolution methods are not very helpful. Our disambiguation model is based on statistical language models. We have investigated the performances of some statistical language model types and parameters in lexical ambiguity resolution for o...

  4. Improving the Estimation of Uncalibrated Fractional Phase Offsets for PPP Ambiguity Resolution

    OpenAIRE

    Xingxing Li; Zhang, X

    2012-01-01

    Integer ambiguity resolution in Precise Point Positioning (PPP) can shorten convergence time and improve accuracy significantly. Uncalibrated Fractional Offsets (UFOs) originating in the satellites destroy the integer nature of carrier phase ambiguities observed at a single station. Several methods have been developed to estimate UFO information from a reference network for PPP ambiguity resolution. In this paper, we present a new approach for estimating Zero-Differenced (ZD) UFOs via float Z...

  5. AMBIGUITY TOLERANCE LEVELS IN SPANISH ACCOUNTING STUDENTS: A COMPARATIVE STUDY

    Directory of Open Access Journals (Sweden)

    Concepción Tejero

    2009-06-01

    Full Text Available La ambigüedad es la percepción de la inadecuación de la información que resulta de determinadas características de un escenario. En situaciones de toma de decisiones, la percepción de ambigüedad puede percibirse como una amenaza y supone un reto cognitivo. En esta línea la literatura ha tratado la incidencia de los niveles de tolerancia a la ambigüedad (AT en la toma de decisiones en contextos empresariales y financieros.Este trabajo trata de estudiar los niveles de AT en una muestra de estudiantes de contabilidad comparándolos con los niveles de otros estudiantes de otras carreras de ciencias sociales. El instrumento usado es la versión española del MSTAT-II (McLain, 2008 y la muestra está compuesta por estudiantes de distintas carreras de ciencias sociales de la Universidad de Huelva. Los resultados indican un alto nivel de consistencia interna del instrumento con esta muestra. Los estudiantes de contabilidad presentan niveles de tolerancia a la ambigüedad más bajos que el resto de sus compañeros en otras carreras. Por último, se debaten las implicaciones educativas para las universidades de estos resultados.Ambiguity is the perception of inadequate information arising from certain characteristics of a situation. In a situation that demands evaluation or choice, the perception of ambiguity is threatening and presents a cognitive challenge. Research has examined AT (Ambiguity Tolerance levels and their influence on decision making in business and financial scenarios. Aims –This paper aims to investigate the AT levels of a sample of accounting students and to compare them with the AT levels of students on other social sciences degree courses. Instrument and Sample - The instrument used is the Spanish version of MSTAT-II (McLain, 2008. The sample is composed of students enrolled on various degree courses at a Spanish University (Universidad de Huelva.Results and implications - The results of the questionnaire present high

  6. The role of ambiguity and discrepancy in the early phases of innovation

    DEFF Research Database (Denmark)

    Laursen, Linda Nhu; Tollestrup, Christian H. T.

    2015-01-01

    Innovation literature mainly focuses on eliminating ambiguity and discrepancy from the early phases of innovation. This study questions this implicit assumption, as it may provide an oversimplified view on, how to attain proficiency. Instead of narrowly focusing on reducing ambiguity...... and discrepancy, we seek to understand if it might be there for a reason. Through a laboratory experiment, we propose ambiguity and discrepancy actually have a function in concept development. Accordingly the paper contributes with a better understanding of, the role ambiguity and discrepancy as triggers of sense...... making in conceptualisation in the early phases of innovation....

  7. Application of genetic algorithm with approximation crossover strategy to ambiguity resolution in PD radar

    Institute of Scientific and Technical Information of China (English)

    ZhangGong; ZhuZhaoda; ZhuNingyi

    2003-01-01

    The genetic algorithm (GA) designed as a general optimization method was applied to the ambiguity resolution of pulse Doppler (PD) radar. The fitness, based on squared error for multi-PRF (pulse repeat frequency) consecutive ordered ranges, was designed. The crossover operator and the conditions of ending in GA were discussed. The relations among the probability of ambiguity resolution of this algorithm, the measurement error and the computational efficiency were analyzed.Simulation results show the GA ambiguity resolution algorithm does better than the sliding window algorithm on the probability of ambiguity resolution.

  8. Moment graphs and representations

    DEFF Research Database (Denmark)

    Jantzen, Jens Carsten

    2012-01-01

    Moment graphs and sheaves on moment graphs are basically combinatorial objects that have be used to describe equivariant intersectiion cohomology. In these lectures we are going to show that they can be used to provide a direct link from this cohomology to the representation theory of simple Lie...

  9. Proportional Representation with Uncertainty

    OpenAIRE

    Francesco De Sinopoli; Giovanna Iannantuoni; Elena Manzoni; Carlos Pimienta

    2014-01-01

    We introduce a model with strategic voting in a parliamentary election with proportional representation and uncertainty about voters’ preferences. In any equilibrium of the model, most voters only vote for those parties whose positions are extreme. In the resulting parliament, a consensus government forms and the policy maximizing the sum of utilities of the members of the government is implemented.

  10. Representation and human reasoning

    NARCIS (Netherlands)

    ter Meulen, Alice G.B.

    2003-01-01

    Interpretation and reasoning are two sides of sharing information. Representations of the context and common ground must capture the rich content of what has been said, by linking to situations in the world as well as to what has been said before, common sense and to the presuppositions and entailme

  11. Between Representation and Eternity

    DEFF Research Database (Denmark)

    Atzbach, Rainer

    2016-01-01

    . At death, an indi- vidual’s corpse and burial primarily reflect the social act of representation during the funeral. The position of the arms, which have incorrectly been used as a chronological tool in Scandinavia, may indicate an evolution from a more collective act of prayer up to the eleventh century...

  12. Inverse variational problem and ambiguity of classical system quantization

    International Nuclear Information System (INIS)

    It is shown that the problem of ambiguity of classical systems quantization is not limited by substitution of classical values for operators and by ordering of noncommutating operators. It is demonstrated that one and the same classical system can be described. Using an infinite number of various (differing more than for a total derivative) Lagrangians or Hamiltonians. The Feynman quantization is used by means of trajectory integrals. The problem of quantization of the classical system of equations of motion turns to be closely related to the inverse variational calculation problem. The inverse variational problem consists in finding a functional proceeding, from given equations, the extremals of which coincide with the solutions of the given equations. It is shown by concrete examples that with different Lagrangians though leading to identical classic equations of motion various quantum systems are obtained

  13. In Praise of Ambiguity: Musical Subtlety and Merleau-Ponty

    Directory of Open Access Journals (Sweden)

    Tiger C. Roholt

    2013-01-01

    Full Text Available When a jazz, rock, or hip-hop drummer strikes certain notes in each measure slightly late, instead of hearing the degree to which those notes are late, we typically hear the effects of those variations; namely, a groove, the "feel" of a rhythm. Slight variations of pitch function similarly. In this essay, I argue that certain analytic theorists go astray due to their preoccupation with the variations themselves. By invoking Maurice Merleau-Ponty's insights into subtle visual perceptions, and his notion of perceptual indeterminacy, I avoid an account of musical subtlety suggested by Daniel Dennett that is too coarse-grained, as well as the bleak conclusion that certain musical subtleties are ineffable, Diana Raffman's view. I conclude that elements of music that are perceived ambiguously can perform a positive function in such aesthetic experiences: they can mediate or foster emergent qualities; moreover, they must be perceived in this way to do so.

  14. Success, failure and ambiguity of the dilution effect among competitors.

    Science.gov (United States)

    Strauss, Alexander T; Civitello, David J; Cáceres, Carla E; Hall, Spencer R

    2015-09-01

    It remains challenging to predict variation in the magnitude of disease outbreaks. The dilution effect seeks to explain this variation by linking multiple host species to disease transmission. It predicts that disease risk increases for a focal host when host species diversity declines. However, when an increase in species diversity does not reduce disease, we are often unable to diagnose why. Here, we increase mechanistic and predictive clarity of the dilution effect with a general trait-based model of disease transmission in multi-host communities. Then, we parameterise and empirically test our model with a multi-generational case study of planktonic disease. The model-experiment combination shows that hosts that vary in competitive ability (R*) and potential to spread disease (R0 ) can produce three qualitatively disparate outcomes of dilution on disease: the dilution effect can succeed, fail, or be ambiguous/irrelevant.

  15. Ambiguity as an Essential Aesthetic Principle in Musical Listening

    DEFF Research Database (Denmark)

    Bonde, Anders

    2006-01-01

    Stravinsky’s Symphonies of Wind Instruments represents a remarkable example of discontinuity. Here, a traditional sense of continuous development is troubled by a sequence of segments, which at first sight seems non-related. However, the noticeable discontinuous gestures appear only as a superfic......Stravinsky’s Symphonies of Wind Instruments represents a remarkable example of discontinuity. Here, a traditional sense of continuous development is troubled by a sequence of segments, which at first sight seems non-related. However, the noticeable discontinuous gestures appear only...... connections’ in the ‘disguise’ of discontinuity implies an either-or viewpoint, which tends to overlook the fact that the musical progression suggests mutually contradistinctive impressions and, as such, is essentially ambiguous. Thus, in this paper it is not my intention to assert that the Symphonies...

  16. Lifting the Gribov ambiguity in Yang-Mills theories

    International Nuclear Information System (INIS)

    We propose a new one-parameter family of Landau gauges for Yang-Mills theories which can be formulated by means of functional integral methods and are thus well suited for analytic calculations, but which are free of Gribov ambiguities and avoid the Neuberger zero problem of the standard Faddeev-Popov construction. The resulting gauge-fixed theory is perturbatively renormalizable in four dimensions and, for what concerns the calculation of ghost and gauge field correlators, it reduces to a massive extension of the Faddeev-Popov action. We study the renormalization group flow of this theory at one-loop and show that it has no Landau pole in the infrared for some - including physically relevant - range of values of the renormalized parameters.

  17. Resolution of overlapping ambiguity strings based on maximum entropy model

    Institute of Scientific and Technical Information of China (English)

    ZHANG Feng; FAN Xiao-zhong

    2006-01-01

    The resolution of overlapping ambiguity strings (OAS) is studied based on the maximum entropy model.There are two model outputs,where either the first two characters form a word or the last two characters form a word.The features of the model include one word in context of OAS,the current OAS and word probability relation of two kinds of segmentation results.OAS in training text is found by the combination of the FMM and BMM segmentation method.After feature tagging they are used to train the maximum entropy model.The People Daily corpus of January 1998 is used in training and testing.Experimental results show a closed test precision of 98.64% and an open test precision of 95.01%.The open test precision is 3,76% better compared with that of the precision of common word probability method.

  18. Effects of the quantisation ambiguities on the Big Bounce dynamics

    CERN Document Server

    Hrycyna, Orest; Szydlowski, Marek

    2008-01-01

    In this paper we investigate dynamics of the modified loop quantum cosmology models using dynamical systems methods. Modifications considered come from the choice of the different field strength operator $\\hat{F}$ and result in different forms of the effective Hamiltonian. Such an ambiguity of the choice of this expression from some class of functions is allowed in the framework of loop quantisation. Our main goal is to show how such modifications can influence the bouncing universe scenario in the loop quantum cosmology. In effective models considered we classify all evolutional paths for all admissible initial conditions. The dynamics is reduced to the form of a dynamical system of the Newtonian type on a 2-dimensional phase plane. These models are equivalent dynamically to the FRW models with the decaying effective cosmological term parametrised by the canonical variable $p$ (or by the scale factor $a$). We find that for the positive cosmological constant there is a class of oscillating models without the ...

  19. The fungus Candida albicans tolerates ambiguity at multiple codons

    Directory of Open Access Journals (Sweden)

    João Salvador Simões

    2016-03-01

    Full Text Available The ascomycete Candida albicans is a normal resident of the gastrointestinal tract of humans and other warm-blooded animals. It occurs in a broad range of body sites and has high capacity to survive and proliferate in adverse environments with drastic changes in oxygen, carbon dioxide, pH, osmolarity, nutrients and temperature. Its biology is unique due to flexible reassignment of the leucine CUG codon to serine and synthesis of statistical proteins. Under standard growth conditions 3% of leucine and 97% of serine are incorporated at CUG sites on a proteome wide scale, but leucine incorporation fluctuates in response to environmental stressors and can be artificially increased up to 98%. In order to determine whether such flexibility also exists at other codons, we have constructed several serine tRNAs that decode various non-cognate codons. Expression of these tRNAs had minor effects on fitness, but growth of the mistranslating strains at different temperatures, in medium with different pH and nutrients composition was often enhanced relatively to the wild type (WT strain, supporting our previous data on adaptive roles of CUG ambiguity in variable growth conditions. Parallel evolution of the recombinant strains (100 generations followed by full genome resequencing identified various strain specific single nucleotide polymorphisms (SNP and one SNP in the deneddylase (JAB1 gene in all strains. Since JAB1 is a subunit of the COP9 signalosome complex, which interacts with cullin (Cdc53p to mediate degradation of a variety of cellular proteins, our data suggest that neddylation plays a key role in tolerance and adaptation to codon ambiguity in C. albicans.

  20. Assimilating ambiguous observations to jointly estimate groundwater recharge and conductivity

    Science.gov (United States)

    Erdal, Daniel; Cirpka, Olaf A.

    2016-04-01

    In coupled modelling of catchments, the groundwater compartment can be an important water storage as well as having influence on both rivers and evapotranspirational fluxes. It is therefore important to parameterize the groundwater model as correctly as possible. Primarily important to regional groundwater flow is the spatially variable hydraulic conductivity. However, also the groundwater recharge, in a coupled system coming from the unsaturated zone but in a stand-alone groundwater model a boundary condition, is also of high importance. As with all subsurface systems, groundwater properties are difficult to observe in reality and their estimation is an ongoing topic in groundwater research and practice. Commonly, we have to rely on time series of groundwater head observations as base for any parameter estimation. Heads, however, have the drawback that they can be ambiguous and may not uniquely define the inverse problem, especially if both recharge and conductivity are seen as unknown. In the presented work we use a 2D virtual groundwater test case to investigate how the prior knowledge of recharge and conductivity influence their respective and joint estimation as spatially variable fields using head data. Using the Ensemble Kalman filter, it is shown that the joint estimation is possible if the prior knowledge is good enough. If the prior is erroneous the a-priori sampled fields cannot be corrected by the data. However, it is also shown that if the prior knowledge is directly wrong the estimated recharge field can resemble the true conductivity field, resulting in a model that meets the observations but has very poor predictive power. The study exemplifies the importance of prior knowledge in the joint estimation of parameters from ambiguous measurements.

  1. Improved ambiguity resolution for URTK with dynamic atmosphere constraints

    Science.gov (United States)

    Tang, Weiming; Liu, Wenjian; Zou, Xuan; Li, Zongnan; Chen, Liang; Deng, Chenlong; Shi, Chuang

    2016-06-01

    Raw observation processing method with prior knowledge of ionospheric delay could strengthen the ambiguity resolution (AR), but it does not make full use of the relatively longer wavelength of wide-lane (WL) observation. Furthermore, the accuracy of calculated atmospheric delays from the regional augmentation information has quite different in quality, while the atmospheric constraint used in the current methods is usually set to an empirical value. A proper constraint, which matches the accuracy of calculated atmospheric delays, can most effectively compensate the residual systematic biases caused by large inter-station distances. Therefore, the standard deviation of the residual atmospheric parameters should be fine-tuned. This paper presents an atmosphere-constrained AR method for undifferenced network RTK (URTK) rover, whose ambiguities are sequentially fixed according to their wavelengths. Furthermore, this research systematically analyzes the residual atmospheric error and finds that it mainly varies along the positional relationship between the rover and the chosen reference stations. More importantly, its ionospheric part of certain location will also be cyclically influenced every day. Therefore, the standard deviation of residual ionospheric error can be modeled by a daily repeated cosine or other functions with the help of data one day before, and applied by rovers as pseudo-observation. With the data collected at 29 stations from a continuously operating reference station network in Guangdong Province (GDCORS) in China, the efficiency of the proposed approach is confirmed by improving the success and error rates of AR for 10-20 % compared to that of the WL-L1-IF one, as well as making much better positioning accuracy.

  2. Neural Computation of Surface Border Ownership and Relative Surface Depth from Ambiguous Contrast Inputs.

    Science.gov (United States)

    Dresp-Langley, Birgitta; Grossberg, Stephen

    2016-01-01

    The segregation of image parts into foreground and background is an important aspect of the neural computation of 3D scene perception. To achieve such segregation, the brain needs information about border ownership; that is, the belongingness of a contour to a specific surface represented in the image. This article presents psychophysical data derived from 3D percepts of figure and ground that were generated by presenting 2D images composed of spatially disjoint shapes that pointed inward or outward relative to the continuous boundaries that they induced along their collinear edges. The shapes in some images had the same contrast (black or white) with respect to the background gray. Other images included opposite contrasts along each induced continuous boundary. Psychophysical results demonstrate conditions under which figure-ground judgment probabilities in response to these ambiguous displays are determined by the orientation of contrasts only, not by their relative contrasts, despite the fact that many border ownership cells in cortical area V2 respond to a preferred relative contrast. Studies are also reviewed in which both polarity-specific and polarity-invariant properties obtain. The FACADE and 3D LAMINART models are used to explain these data. PMID:27516746

  3. Perceptual switch rates with ambiguous structure-from-motion figures in bipolar disorder.

    Science.gov (United States)

    Krug, Kristine; Brunskill, Emma; Scarna, Antonina; Goodwin, Guy M; Parker, Andrew J

    2008-08-22

    Slowing of the rate at which a rivalrous percept switches from one configuration to another has been suggested as a potential trait marker for bipolar disorder. We measured perceptual alternations for a bistable, rotating, structure-from-motion cylinder in bipolar and control participants. In a control task, binocular depth rendered the direction of cylinder rotation unambiguous to monitor participants' performance and attention during the experimental task. A particular direction of rotation was perceptually stable, on average, for 33.5s in participants without psychiatric diagnosis. Euthymic, bipolar participants showed a slightly slower rate of switching between the two percepts (percept duration 42.3s). Under a parametric analysis of the best-fitting model for individual participants, this difference was statistically significant. However, the variability within groups was high, so this difference in average switch rates was not big enough to serve as a trait marker for bipolar disorder. We also found that low-level visual capacities, such as stereo threshold, influence perceptual switch rates. We suggest that there is no single brain location responsible for perceptual switching in all different ambiguous figures and that perceptual switching is generated by the actions of local cortical circuitry. PMID:18463054

  4. Accessing characters in spoken Chinese disyllables: An ERP study on the resolution of auditory ambiguity.

    Science.gov (United States)

    Chen, Xuqian; Huang, Guoliang; Huang, Jian

    2016-01-01

    Chinese differs from most Indo-European languages in its phonological, lexical, and syntactic structures. One of its unique properties is the abundance of homophones at the monosyllabic/morphemic level, with the consequence that monosyllabic homophones are all ambiguous in speech perception. Two-morpheme Chinese words can be composed of two high homophone-density morphemes (HH words), two low homophone-density morphemes (LL words), or one high and one low homophone-density morphemes (LH or HL words). The assumption of a simple inhibitory homophone effect is called into question in the case of disyllabic spoken word recognition, in which the recognition of one morpheme is affected by semantic information given by the other. Event-related brain potentials (ERPs) were used to trace on-line competitions among morphemic homophones in accessing Chinese disyllables. Results showing significant differences in ERP amplitude when comparing LL and LH words, but not when comparing LL and HL words, suggested that the first morpheme cannot be accessed without feedback from the second morpheme. Most importantly, analyses of N400 amplitude among different densities showed a converse homophone effect in which LL words, rather than LH or HL words, triggered larger N400. These findings provide strong evidence of a dynamic integration system at work during spoken Chinese disyllable recognition. PMID:26589544

  5. Brain herniation

    Science.gov (United States)

    ... herniation; Uncal herniation; Subfalcine herniation; Tonsillar herniation; Herniation - brain ... Brain herniation occurs when something inside the skull produces pressure that moves brain tissues. This is most ...

  6. Creating abstract topographic representations: implications for coding, learning and reasoning.

    Science.gov (United States)

    Tinsley, Chris J

    2009-06-01

    Topographic maps are a fundamental and ubiquitous feature of the sensory and motor regions of the brain. There is less evidence for the existence of conventional topographic maps in associational areas of the brain such as the prefrontal cortex and parietal cortex. The existence of topographically arranged anatomical projections is far more widespread and occurs in associational regions of the brain as well as sensory and motor regions: this points to a more widespread existence of topographically organised maps within associational cortex than currently recognised. Indeed, there is increasing evidence that abstract topographic representations may also occur in these regions. For example, a topographic mnemonic map of visual space has been described in the dorsolateral prefrontal cortex and topographically arranged visuospatial attentional signals have been described in parietal association cortex. This article explores how abstract representations might be extracted from sensory topographic representations and subsequently code abstract information. Finally a simple model is presented that shows how abstract topographic representations could be integrated with other information within the brain to solve problems or form abstract associations. The model uses correlative firing to detect associations between different types of stimuli. It is flexible because it can produce correlations between information represented in a topographic or non-topographic coordinate system. It is proposed that a similar process could be used in high-level cognitive operations such as learning and reasoning.

  7. Standard model of knowledge representation

    Science.gov (United States)

    Yin, Wensheng

    2016-09-01

    Knowledge representation is the core of artificial intelligence research. Knowledge representation methods include predicate logic, semantic network, computer programming language, database, mathematical model, graphics language, natural language, etc. To establish the intrinsic link between various knowledge representation methods, a unified knowledge representation model is necessary. According to ontology, system theory, and control theory, a standard model of knowledge representation that reflects the change of the objective world is proposed. The model is composed of input, processing, and output. This knowledge representation method is not a contradiction to the traditional knowledge representation method. It can express knowledge in terms of multivariate and multidimensional. It can also express process knowledge, and at the same time, it has a strong ability to solve problems. In addition, the standard model of knowledge representation provides a way to solve problems of non-precision and inconsistent knowledge.

  8. Standard model of knowledge representation

    Science.gov (United States)

    Yin, Wensheng

    2016-03-01

    Knowledge representation is the core of artificial intelligence research. Knowledge representation methods include predicate logic, semantic network, computer programming language, database, mathematical model, graphics language, natural language, etc. To establish the intrinsic link between various knowledge representation methods, a unified knowledge representation model is necessary. According to ontology, system theory, and control theory, a standard model of knowledge representation that reflects the change of the objective world is proposed. The model is composed of input, processing, and output. This knowledge representation method is not a contradiction to the traditional knowledge representation method. It can express knowledge in terms of multivariate and multidimensional. It can also express process knowledge, and at the same time, it has a strong ability to solve problems. In addition, the standard model of knowledge representation provides a way to solve problems of non-precision and inconsistent knowledge.

  9. Realizations of the Canonical Representation

    Indian Academy of Sciences (India)

    M K Vemuri

    2008-02-01

    A characterisation of the maximal abelian subalgebras of the bounded operators on Hilbert space that are normalised by the canonical representation of the Heisenberg group is given. This is used to classify the perfect realizations of the canonical representation.

  10. Brain areas activated by uncertain reward-based decision-making in healthy volunteers

    OpenAIRE

    Guo, Zongjun; Chen, Juan; Liu, Shien; Li, Yuhuan; Sun, Bo; Gao, Zhenbo

    2013-01-01

    Reward-based decision-making has been found to activate several brain areas, including the ventrolateral prefrontal lobe, orbitofrontal cortex, anterior cingulate cortex, ventral striatum, and mesolimbic dopaminergic system. In this study, we observed brain areas activated under three degrees of uncertainty in a reward-based decision-making task (certain, risky, and ambiguous). The tasks were presented using a brain function audiovisual stimulation system. We conducted brain scans of 15 healt...

  11. Harmonic Analysis and Group Representation

    CERN Document Server

    Figa-Talamanca, Alessandro

    2011-01-01

    This title includes: Lectures - A. Auslander, R. Tolimeri - Nilpotent groups and abelian varieties, M Cowling - Unitary and uniformly bounded representations of some simple Lie groups, M. Duflo - Construction de representations unitaires d'un groupe de Lie, R. Howe - On a notion of rank for unitary representations of the classical groups, V.S. Varadarajan - Eigenfunction expansions of semisimple Lie groups, and R. Zimmer - Ergodic theory, group representations and rigidity; and, Seminars - A. Koranyi - Some applications of Gelfand pairs in classical analysis.

  12. Constructing visual representations

    DEFF Research Database (Denmark)

    Huron, Samuel; Jansen, Yvonne; Carpendale, Sheelagh

    2014-01-01

    The accessibility of infovis authoring tools to a wide audience has been identified as a major research challenge. A key task in the authoring process is the development of visual mappings. While the infovis community has long been deeply interested in finding effective visual mappings......, comparatively little attention has been placed on how people construct visual mappings. In this paper, we present the results of a study designed to shed light on how people transform data into visual representations. We asked people to create, update and explain their own information visualizations using only...... tangible building blocks. We learned that all participants, most of whom had little experience in visualization authoring, were readily able to create and talk about their own visualizations. Based on our observations, we discuss participants’ actions during the development of their visual representations...

  13. Expanded, but not regulated: ambiguity in home-care policy in Ireland.

    Science.gov (United States)

    Timonen, Virpi; Doyle, Martha; O'Dwyer, Ciara

    2012-05-01

    This article argues that home-care policy in Ireland was ambiguous throughout the first decade of the 21st century: policy-makers expanded home care, but failed to develop policies to govern this expanded provision. As a result, home care became more widely available in the absence of a framework to govern access to services and to regulate care providers. We analysed official policy documents, statistics and policy critiques published between 2000 and 2010 in order to understand this incongruity between the expansion of home-care services and the failure to develop policies to govern access to and quality of services. The key factors that motivated home-care expansion in the Irish case were: (1) problems in the acute hospital sector and the perception of home care as a partial solution to these (political blame avoidance) and (2) significant GDP growth (until 2007) that provided politicians with the means to fund expansion in home-care services (political credit claiming). The key factors that inhibited the development of a policy framework to govern home-care services were: (1) weak governance structures in health services and decision-making at national level based on short-term political gain; (2) Ireland's adherence to the liberal welfare state model and concern about uncontrollable care costs in the face of population ageing; (3) until 2010, paucity of attention to home-care issues in the Irish media and (4) weak provider interest representation. The recent budgetary cutbacks in Ireland bring into sharp relief the political expediency of an unregulated domiciliary care sector and absence of entitlements to home care. We conclude that the forces that drive expanded provision are different from drivers of policy to govern home care and that weakness of governance structures and political advantages of the absence of regulation are the main reasons for the lack of standards and entitlement rules. PMID:22168468

  14. Comprehension and Representation in Translation

    Institute of Scientific and Technical Information of China (English)

    徐玉萍

    2010-01-01

    Transhfion is the faithful rcpresentation in one language of the thought, content, feeling and style written in another language. It involves two processes: comprehension and representation. Correct comprehension is the base for adequate representation. Criteria for good representation lies in two points: the version should be faithful to the original, and the version should be as intelligible as possible.

  15. Multiple Forms of Dynamic Representation

    Science.gov (United States)

    Ainsworth, Shaaron; VanLabeke, Nicolas

    2004-01-01

    The terms dynamic representation and animation are often used as if they are synonymous, but in this paper we argue that there are multiple ways to represent phenomena that change over time. Time-persistent representations show a range of values over time. Time-implicit representations also show a range of values but not the specific times when…

  16. Developing representations of compound stimuli

    NARCIS (Netherlands)

    I. Visser; M.E.J. Raijmakers

    2012-01-01

    Classification based on multiple dimensions of stimuli is usually associated with similarity-based representations, whereas uni-dimensional classifications are associated with rule-based representations. This paper studies classification of stimuli and category representations in school-aged childre

  17. Exploring the Relationship between Tolerance of Ambiguity of EFL Learners and Their Vocabulary Knowledge

    Science.gov (United States)

    Basöz, Tutku

    2015-01-01

    Learning a new language is akin to exploring an unknown land as ambiguous situations are prevalent in language learning. Ambiguity tolerance, which can hinder or facilitate language learning, is considered as an important learning style. The purpose of the present study was to understand how tolerant/intolerant EFL learners are of foreign language…

  18. Role Ambiguity and Self-Efficacy: The Moderating Effects of Goal Orientation and Procedural Justice

    Science.gov (United States)

    Li, Andrew; Bagger, Jessica

    2008-01-01

    The present study investigated variables that moderated the relationship between role ambiguity and self-efficacy. Results of a field study found support for the moderating role of learning goal orientation, such that the relationship between role ambiguity and self-efficacy was weaker when learning goal orientation was high. In addition, we found…

  19. Medical Student and Junior Doctors' Tolerance of Ambiguity: Development of a New Scale

    Science.gov (United States)

    Hancock, Jason; Roberts, Martin; Monrouxe, Lynn; Mattick, Karen

    2015-01-01

    The practice of medicine involves inherent ambiguity, arising from limitations of knowledge, diagnostic problems, complexities of treatment and outcome and unpredictability of patient response. Research into doctors' tolerance of ambiguity is hampered by poor conceptual clarity and inadequate measurement scales. We aimed to create and pilot a…

  20. Learning the Language of Evolution: Lexical Ambiguity and Word Meaning in Student Explanations

    Science.gov (United States)

    Rector, Meghan A.; Nehm, Ross H.; Pearl, Dennis

    2013-06-01

    Our study investigates the challenges introduced by students' use of lexically ambiguous language in evolutionary explanations. Specifically, we examined students' meaning of five key terms incorporated into their written evolutionary explanations: pressure, select, adapt, need, and must. We utilized a new technological tool known as the Assessment Cascade System (ACS) to investigate the frequency with which biology majors spontaneously used lexically ambiguous language in evolutionary explanations, as well as their definitions and explanations of what they meant when they used such terms. Three categories of language were identified and examined in this study: terms with Dual Ambiguity, Incompatible Ambiguity, and Unintended Ambiguity. In the sample of 1282 initial evolutionary explanations, 81 % of students spontaneously incorporated lexically ambiguous language at least once. Furthermore, the majority of these initial responses were judged to be inaccurate from a scientific point of view. While not significantly related to gender, age, or reading/writing ability, students' use of contextually appropriate evolutionary language ( pressure and adapt) was significantly associated with academic performance in biology. Comparisons of initial responses to follow-up responses demonstrated that the majority of student explanations were not reinterpreted after consideration of the follow-up response; nevertheless, a sizeable minority was interpreted differently. Most cases of interpretation change were a consequence of resolving initially ambiguous responses, rather than a change of accuracy, resulting in an increased understanding of students' evolutionary explanations. We discuss a series of implications of lexical ambiguity for evolution education.

  1. Exploiting Lexical Ambiguity to Help Students Understand the Meaning of "Random"

    Science.gov (United States)

    Kaplan, Jennifer J.; Rogness, Neal T.; Fisher, Diane G.

    2014-01-01

    Words that are part of colloquial English but used differently in a technical domain may possess lexical ambiguity. The use of such words by instructors may inhibit student learning if incorrect connections are made by students between the technical and colloquial meanings. One fundamental word in statistics that has lexical ambiguity for students…

  2. Exploiting Degrees of Inflectional Ambiguity: Stem Form and the Time Course of Morphological Processing

    Science.gov (United States)

    Jarvikivi, Juhani; Pyykkonen, Pirita; Niemi, Jussi

    2009-01-01

    The authors compared sublexical and supralexical approaches to morphological processing with unambiguous and ambiguous inflected words and words with ambiguous stems in 3 masked and unmasked priming experiments in Finnish. Experiment 1 showed equal facilitation for all prime types with a short 60-ms stimulus onset asynchrony (SOA) but significant…

  3. Identification and Definition of Lexically Ambiguous Words in Statistics by Tutors and Students

    Science.gov (United States)

    Richardson, Alice M.; Dunn, Peter K.; Hutchins, Rene

    2013-01-01

    Lexical ambiguity arises when a word from everyday English is used differently in a particular discipline, such as statistics. This paper reports on a project that begins by identifying tutors' perceptions of words that are potentially lexically ambiguous to students, in two different ways. Students' definitions of nine lexically…

  4. Morpho-Semantic Processing in Word Recognition: Evidence from Balanced and Biased Ambiguous Morphemes

    Science.gov (United States)

    Tsang, Yiu-Kei; Chen, Hsuan-Chih

    2013-01-01

    The role of morphemic meaning in Chinese word recognition was examined with the masked and unmasked priming paradigms. Target words contained ambiguous morphemes biased toward the dominant or the subordinate meanings. Prime words either contained the same ambiguous morphemes in the subordinate interpretations or were unrelated to the targets. In…

  5. Early Morphological Processing Is Sensitive to Morphemic Meanings: Evidence from Processing Ambiguous Morphemes

    Science.gov (United States)

    Tsang, Yiu-Kei; Chen, Hsuan-Chih

    2013-01-01

    In three priming experiments, we investigated whether the meanings of ambiguous morphemes were activated during word recognition. Using a meaning generation task, Experiment 1 demonstrated that the dominant meaning of individually presented ambiguous morphemes was reported more often than did other less frequent meanings. Also, participants tended…

  6. In the Face of Uncertainty: A Twin Study of Ambiguous Information, Anxiety and Depression in Children

    Science.gov (United States)

    Eley, Thalia C.; Gregory, Alice M.; Lau, Jennifer Y. F.; McGuffin, Peter; Napolitano, Maria; Rijsdijk, Fruhling V.; Clark, David M.

    2008-01-01

    Anxiety and depression share genetic influences, and have been associated with similar cognitive biases. Psychological theories of anxiety and depression highlight threat interpretations of ambiguity. Little is known about whether genes influence cognitive style, or its links to symptoms. We assessed ambiguous word and scenario interpretations,…

  7. As Far As Words Go: Activities for Understanding Ambiguous Language and Humor, Revised Edition

    Science.gov (United States)

    Spector, Cecile Cyrul

    2009-01-01

    Understanding ambiguous words, phrases, and sentences is an important part of reading well, communicating skillfully, and enjoying humor based on word play. With this seven-unit activity book--filled with creative, ready-to-use activities based on jokes and puns--students will learn how to decipher the language ambiguities they encounter inside…

  8. [Time perceptions and representations].

    Science.gov (United States)

    Tordjman, S

    2015-09-01

    Representations of time and time measurements depend on subjective constructs that vary according to changes in our concepts, beliefs, societal needs and technical advances. Similarly, the past, the future and the present are subjective representations that depend on each individual's psychic time and biological time. Therefore, there is no single, one-size-fits-all time for everyone, but rather a different, subjective time for each individual. We need to acknowledge the existence of different inter-individual times but also intra-individual times, to which different functions and different rhythms are attached, depending on the system of reference. However, the construction of these time perceptions and representations is influenced by objective factors (physiological, physical and cognitive) related to neuroscience which will be presented and discussed in this article. Thus, studying representation and perception of time lies at the crossroads between neuroscience, human sciences and philosophy. Furthermore, it is possible to identify several constants among the many and various representations of time and their corresponding measures, regardless of the system of time reference. These include the notion of movements repeated in a stable rhythmic pattern involving the recurrence of the same interval of time, which enables us to define units of time of equal and invariable duration. This rhythmicity is also found at a physiological level and contributes through circadian rhythms, in particular the melatonin rhythm, to the existence of a biological time. Alterations of temporality in mental disorders will be also discussed in this article illustrated by certain developmental disorders such as autism spectrum disorders. In particular, the hypothesis will be developed that children with autism would need to create discontinuity out of continuity through stereotyped behaviors and/or interests. This discontinuity repeated at regular intervals could have been

  9. The field representation language.

    Science.gov (United States)

    Tsafnat, Guy

    2008-02-01

    The complexity of quantitative biomedical models, and the rate at which they are published, is increasing to a point where managing the information has become all but impossible without automation. International efforts are underway to standardise representation languages for a number of mathematical entities that represent a wide variety of physiological systems. This paper presents the Field Representation Language (FRL), a portable representation of values that change over space and/or time. FRL is an extensible mark-up language (XML) derivative with support for large numeric data sets in Hierarchical Data Format version 5 (HDF5). Components of FRL can be reused through unified resource identifiers (URI) that point to external resources such as custom basis functions, boundary geometries and numerical data. To demonstrate the use of FRL as an interchange we present three models that study hyperthermia cancer treatment: a fractal model of liver tumour microvasculature; a probabilistic model simulating the deposition of magnetic microspheres throughout it; and a finite element model of hyperthermic treatment. The microsphere distribution field was used to compute the heat generation rate field around the tumour. We used FRL to convey results from the microsphere simulation to the treatment model. FRL facilitated the conversion of the coordinate systems and approximated the integral over regions of the microsphere deposition field. PMID:17434811

  10. A study of the ambiguity in the solutions to the Diophantine equation for Chern numbers

    Science.gov (United States)

    Avron, J. E.; Kenneth, O.; Yehoshua, G.

    2014-05-01

    The Chern numbers for Hofstadter models with rational flux 2πp/q are partially determined by a Diophantine equation. A mod q ambiguity remains. The resolution of this ambiguity is only known for the rectangular lattice with nearest neighbors hopping where it has the form of a ‘window condition’. We study a Hofstadter butterfly on the triangular lattice for which the resolution of ambiguity is open. In the model many pairs (p, q) satisfy a window condition which is shifted relative to the window of the square model. However, we also find pairs (p, q) where the Chern numbers do not belong to any contiguous window. This shows that the rectangular model and the one we study on the triangular lattice are not adiabatically connected: many gaps must close. Our results suggest the conjecture that the mod q ambiguity in the Diophantine equation generically reduces to a sign ambiguity.

  11. Dealing With Uncertainty: Testing Risk- and Ambiguity-Attitude Across Adolescence.

    Science.gov (United States)

    Blankenstein, Neeltje E; Crone, Eveline A; van den Bos, Wouter; van Duijvenvoorde, Anna C K

    2016-01-01

    Attitudes to risk (known probabilities) and attitudes to ambiguity (unknown probabilities) are separate constructs that influence decision making, but their development across adolescence remains elusive. We administered a choice task to a wide adolescent age-range (N = 157, 10-25 years) to disentangle risk- and ambiguity-attitudes using a model-based approach. Additionally, this task was played in a social context, presenting choices from a high risk-taking peer. We observed age-related changes in ambiguity-attitude, but not risk-attitude. Also, ambiguity-aversion was negatively related to real-life risk taking. Finally, the social context influenced only risk-attitudes. These results highlight the importance of disentangling risk- and ambiguity-attitudes in adolescent risk taking. PMID:27028162

  12. Emolabeling effectively reduces the influence of ambiguous labeling on food packages among grocery store shoppers.

    Science.gov (United States)

    Privitera, Gregory J; Brown, Caitlin J; Gillespie, James J

    2014-12-16

    Despite increased regulations and policy enforcement for nutrition labeling, ambiguous labels on food items can still have deleterious effects on consumer perceptions of health. The present study used a counterbalanced within-subjects design to test if emolabeling - the use of emoticons to convey health information (happy = healthy; sad = not healthy) - will reduce the effects of ambiguous labels on consumer perceptions of the healthfulness of a food item. 85 grocery store shoppers were shown nutrition labels for a low calorie (LC) and a high calorie (HC) food with/without emolabels, and with an ambiguous label that either implied the food was healthy or unhealthy. Results showed that emolabels reduced the effectiveness of ambiguous labels: consumers rated the LC food as healthier and the HC food as less healthy when emolabels were added. The results suggest that, if implemented, this image-based emolabeling system could possibly be an effective buffer against the use of ambiguous labeling by food manufacturers.

  13. GP consortia: navigating ambiguity to produce greater public value?

    Science.gov (United States)

    Holbeche, Linda

    2011-05-01

    The UK's NHS is about to be significantly remodelled according to a white paper published in July 2010 that outlines the devolution of commissioning responsibilities away from strategic health authorities and primary care trusts to consortia of GPs, which are to be established at local level. Details of how the new GP consortia will operate are as yet unclear, but in essence they will be strategic alliances and it is likely that they will develop more or less formal arrangements between consortia partners, such as those of a commercial joint venture. This article draws on primary research into strategic alliances between organizations in all sectors. It suggests that there can be significant challenges for those working within strategic alliances, given that these tend to be beset by ambiguity and political tensions. In a context of ever greater transparency and accountability, it will be crucial to attend to the human aspects of strategic alliances since these represent significant risk if neglected. Conversely, alliances also offer the opportunity to develop the synergy of people, organizations and communities to deliver greater public value. Successful collaborations need to get three things right: governance, operations and behaviours. Relationships between consortia partners have a significant bearing on their ability to deliver desired outcomes. They must be able to build and maintain trust. Consortia partners will need sophisticated negotiating and stakeholder management skills and must be able to engage the public in setting the strategic goals for which they will be accountable. They also need strategic and operational management skills and must be able to cope with ambiguity and manage complexity. This paper argues that specific forms of leadership are needed in collaborative arrangements to mobilize people for positive action. People must work together by willingly and effectively pooling their initiative and expertise, and create a product or energy

  14. Neural representations of magnitude for natural and rational numbers.

    Science.gov (United States)

    DeWolf, Melissa; Chiang, Jeffrey N; Bassok, Miriam; Holyoak, Keith J; Monti, Martin M

    2016-11-01

    Humans have developed multiple symbolic representations for numbers, including natural numbers (positive integers) as well as rational numbers (both fractions and decimals). Despite a considerable body of behavioral and neuroimaging research, it is currently unknown whether different notations map onto a single, fully abstract, magnitude code, or whether separate representations exist for specific number types (e.g., natural versus rational) or number representations (e.g., base-10 versus fractions). We address this question by comparing brain metabolic response during a magnitude comparison task involving (on different trials) integers, decimals, and fractions. Univariate and multivariate analyses revealed that the strength and pattern of activation for fractions differed systematically, within the intraparietal sulcus, from that of both decimals and integers, while the latter two number representations appeared virtually indistinguishable. These results demonstrate that the two major notations formats for rational numbers, fractions and decimals, evoke distinct neural representations of magnitude, with decimals representations being more closely linked to those of integers than to those of magnitude-equivalent fractions. Our findings thus suggest that number representation (base-10 versus fractions) is an important organizational principle for the neural substrate underlying mathematical cognition.

  15. Multiple forms of dynamic representation

    OpenAIRE

    Ainsworth, Shaaron E.; Van Labeke, Nicolas

    2004-01-01

    The terms dynamic representation and animation are often used as if they are synonymous, but in this paper we argue that there are multiple ways to represent phenomena that change over time. Time-persistent representations show a range of values over time. Time-implicit representations also show a range of values but not the specific times when the values occur. Time-singular representations show only a single point of time. In this paper, we examine the use of dynamic representations in inst...

  16. Ambiguous Capture: Collaborative Capitalism and the Meningitis Vaccine Project.

    Science.gov (United States)

    Graham, Janice

    2016-01-01

    The primary health care approach advanced at Alma Ata to address social determinants of health was replaced by selective health care a year later at Bellagio. Subsequently, immunization was endorsed as a cost-effective technical intervention to combat targeted infectious diseases. Multilateral efforts to collaborate on immunization as a universal public health good ambiguously capture the interests of the world's governments as well as private, public, and not-for-profit institutions. Global assemblages of scientists, governments, industry and nongovernmental organizations now work in public-private partnerships to develop and make essential vaccines accessible, with vaccines marketed as single fix solutions for global health. Drawing from ethnographic fieldwork in France and Burkina Faso that followed the development, regulation, and implementation of the group A meningococcal conjugate vaccine for sub-Saharan Africa, in this article I describe events during and after the development of MenAfriVac. A technological success narrative steeped in collaborative capitalist rhetoric disguises neglected health care systems.

  17. Ambiguous Capture: Collaborative Capitalism and the Meningitis Vaccine Project.

    Science.gov (United States)

    Graham, Janice

    2016-01-01

    The primary health care approach advanced at Alma Ata to address social determinants of health was replaced by selective health care a year later at Bellagio. Subsequently, immunization was endorsed as a cost-effective technical intervention to combat targeted infectious diseases. Multilateral efforts to collaborate on immunization as a universal public health good ambiguously capture the interests of the world's governments as well as private, public, and not-for-profit institutions. Global assemblages of scientists, governments, industry and nongovernmental organizations now work in public-private partnerships to develop and make essential vaccines accessible, with vaccines marketed as single fix solutions for global health. Drawing from ethnographic fieldwork in France and Burkina Faso that followed the development, regulation, and implementation of the group A meningococcal conjugate vaccine for sub-Saharan Africa, in this article I describe events during and after the development of MenAfriVac. A technological success narrative steeped in collaborative capitalist rhetoric disguises neglected health care systems. PMID:27027575

  18. Direct Speaker Gaze Promotes Trust in Truth-Ambiguous Statements.

    Science.gov (United States)

    Kreysa, Helene; Kessler, Luise; Schweinberger, Stefan R

    2016-01-01

    A speaker's gaze behaviour can provide perceivers with a multitude of cues which are relevant for communication, thus constituting an important non-verbal interaction channel. The present study investigated whether direct eye gaze of a speaker affects the likelihood of listeners believing truth-ambiguous statements. Participants were presented with videos in which a speaker produced such statements with either direct or averted gaze. The statements were selected through a rating study to ensure that participants were unlikely to know a-priori whether they were true or not (e.g., "sniffer dogs cannot smell the difference between identical twins"). Participants indicated in a forced-choice task whether or not they believed each statement. We found that participants were more likely to believe statements by a speaker looking at them directly, compared to a speaker with averted gaze. Moreover, when participants disagreed with a statement, they were slower to do so when the statement was uttered with direct (compared to averted) gaze, suggesting that the process of rejecting a statement as untrue may be inhibited when that statement is accompanied by direct gaze. PMID:27643789

  19. Constrained quantities in uncertainty quantification. Ambiguity and tips to follow

    International Nuclear Information System (INIS)

    The nuclear community relies heavily on computer codes and numerical tools. The results of such computations can only be trusted if they are augmented by proper sensitivity and uncertainty (S and U) studies. This paper presents some aspects of S and U analysis when constrained quantities are involved, such as the fission spectrum or the isotopic distribution of elements. A consistent theory is given for the derivation and interpretation of constrained sensitivities as well as the corresponding covariance matrix normalization procedures. It is shown that if the covariance matrix violates the “generic zero column and row sum” condition, normalizing it is equivalent to constraining the sensitivities, but since both can be done in many ways different sensitivity coefficients and uncertainties can be derived. This makes results ambiguous, underlining the need for proper covariance data. It is also highlighted that the use of constrained sensitivity coefficients derived with a constraining procedure that is not idempotent can lead to biased results in uncertainty propagation. The presented theory is demonstrated on an analytical case and a numerical example involving the fission spectrum, both confirming the main conclusions of this research. (author)

  20. Possible ambiguities in the equation of state for neutron stars

    Energy Technology Data Exchange (ETDEWEB)

    Cheoun, Myung-Ki; Miyatsu, Tsuyoshi; Ryu, C. Y. [Department of Physics, Soongsil University, Seoul 156-743 (Korea, Republic of); Deliduman, Cemsinan [Department of Physics, Mimar Sinan Fine Arts University, Bomonti 34380, Istanbul (Turkey); Güngör, Can; Keleş, Vildan [Istanbul Technical University, Faculty of Science and Letters, Physics Engineering Department, Maslak 34469, Istanbul (Turkey); Kajino, Toshitaka [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan and Department of Astronomy, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033 (Japan); Mathews, Grant J. [Center for Astrophysics, Department of Physics, University of Notre Dame, IN 46556 (United States)

    2014-05-02

    We addressed possible ambiguities on the properties of neutron stars (NSs) estimated in theoretical sides. First, roles of hyperons inside the NS are discussed through various relativistic mean field (RMF) theories. In particular, the extension of SU(6) spin-flavor symmetry to SU(3) flavor symmetry is shown to give rise to the increase of hyperon threshold density, similarly to the Fock term effects in RMF theories. As a result, about 2.0 solar mass is obtained with the hyperons. Second, the effect by the modified f(R) gravity, which leaves a room for the dark energy in the Einstein equation to be taken into account, is discussed for the NS in a strong magnetic field (MF). Our results show that the modified gravity with the Kaluza-Klein electro-magnetism theory expanded in terms of a length scale parameter may reasonably describe the NS in strong MF, so called magnetar. Even the super-soft equation of state is shown to be revived by the modified f(R) gravity.

  1. Ambiguities and Asymmetries in Consent and Refusal: Reply to Manson.

    Science.gov (United States)

    Lawlor, Rob

    2016-06-01

    John Harris claims that is it 'palpable nonsense' to suggest that 'a child (or anyone) might competently consent to a treatment but not be competent to refuse it.' In 'Transitional Paternalism: How Shared Normative Powers Give Rise to the Asymmetry of Adolescent Consent and Refusal' Neil Manson aims to explain away the apparent oddness of this asymmetry of consent and refusal, by appealing to the idea of shared normative powers, presenting joint bank accounts as an example. In this article, I will argue that Manson's account fails to explain away the oddness. Rather, I will argue that there are ambiguities to which Manson has not paid sufficient attention. In fact, as odd as it may sound, I argue that Manson actually agrees with Harris (at least in relation to the asymmetry of competence). He fails to recognize that he agrees with Harris because he is not careful enough to distinguish between different asymmetries, which I have labelled the asymmetries of choice, permissibility and competence.

  2. Direct Speaker Gaze Promotes Trust in Truth-Ambiguous Statements

    Science.gov (United States)

    Kessler, Luise; Schweinberger, Stefan R.

    2016-01-01

    A speaker’s gaze behaviour can provide perceivers with a multitude of cues which are relevant for communication, thus constituting an important non-verbal interaction channel. The present study investigated whether direct eye gaze of a speaker affects the likelihood of listeners believing truth-ambiguous statements. Participants were presented with videos in which a speaker produced such statements with either direct or averted gaze. The statements were selected through a rating study to ensure that participants were unlikely to know a-priori whether they were true or not (e.g., “sniffer dogs cannot smell the difference between identical twins”). Participants indicated in a forced-choice task whether or not they believed each statement. We found that participants were more likely to believe statements by a speaker looking at them directly, compared to a speaker with averted gaze. Moreover, when participants disagreed with a statement, they were slower to do so when the statement was uttered with direct (compared to averted) gaze, suggesting that the process of rejecting a statement as untrue may be inhibited when that statement is accompanied by direct gaze. PMID:27643789

  3. Computing with scale-invariant neural representations

    Science.gov (United States)

    Howard, Marc; Shankar, Karthik

    The Weber-Fechner law is perhaps the oldest quantitative relationship in psychology. Consider the problem of the brain representing a function f (x) . Different neurons have receptive fields that support different parts of the range, such that the ith neuron has a receptive field at xi. Weber-Fechner scaling refers to the finding that the width of the receptive field scales with xi as does the difference between the centers of adjacent receptive fields. Weber-Fechner scaling is exponentially resource-conserving. Neurophysiological evidence suggests that neural representations obey Weber-Fechner scaling in the visual system and perhaps other systems as well. We describe an optimality constraint that is solved by Weber-Fechner scaling, providing an information-theoretic rationale for this principle of neural coding. Weber-Fechner scaling can be generated within a mathematical framework using the Laplace transform. Within this framework, simple computations such as translation, correlation and cross-correlation can be accomplished. This framework can in principle be extended to provide a general computational language for brain-inspired cognitive computation on scale-invariant representations. Supported by NSF PHY 1444389 and the BU Initiative for the Physics and Mathematics of Neural Systems,.

  4. Music as Representational Art

    OpenAIRE

    Walker, Daniel

    2014-01-01

    ABSTRACT OF THE DISSERTATIONVolume IMusic as Representational ArtVolume IIAwakeningbyDaniel WalkerDoctor of Philosophy in MusicUniversity of California, Los Angeles, 2014Professor Ian Krouse, ChairThere are two volumes to this dissertation; the first is a monograph, and the second is a musical composition, both of which are described below.Volume IMusic is a language that can be used to express a vast range of ideas and emotions. It has been part of the human experience since before recorded ...

  5. Representation of the Divine

    DEFF Research Database (Denmark)

    Loddegaard, Anne

    2012-01-01

    out of place in a novel belonging to the serious combat literature of the Catholic Revival, and the direct representation of the supernatural is also surprising because previous Catholic Revival novelists, such as Léon Bloy and Karl-Joris Huysmans, maintain a realistic, non-magical world and deal...... Satan episode in Under Satan’s Sun is neither a break with the seriousness nor with the realism of the Catholic novel. On the basis of Tvetan Todorov’s definition of the traditional fantastic tale, the analysis shows that only the beginning of the fantastic episode follows Todorov’s definition...

  6. Representation of the Divine

    DEFF Research Database (Denmark)

    Loddegaard, Anne

    2009-01-01

    out of place in a novel belonging to the serious combat literature of the Catholic Revival, and the direct representation of the supernatural is also surprising because previous Catholic Revival novelists, such as Léon Bloy and Karl-Joris Huysmans, maintain a realistic, non-magical world and deal...... Satan episode in Under Satan’s Sun is neither a break with the seriousness nor with the realism of the Catholic novel. On the basis of Tvetan Todorov’s definition of the traditional fantastic tale, the analysis shows that only the beginning of the fantastic episode follows Todorov’s definition...

  7. Representations of commonsense knowledge

    CERN Document Server

    Davis, Ernest

    1990-01-01

    Representations of Commonsense Knowledge provides a rich language for expressing commonsense knowledge and inference techniques for carrying out commonsense knowledge. This book provides a survey of the research on commonsense knowledge.Organized into 10 chapters, this book begins with an overview of the basic ideas on artificial intelligence commonsense reasoning. This text then examines the structure of logic, which is roughly analogous to that of a programming language. Other chapters describe how rules of universal validity can be applied to facts known with absolute certainty to deduce ot

  8. Beyond natural numbers: negative number representation in parietal cortex.

    Science.gov (United States)

    Blair, Kristen P; Rosenberg-Lee, Miriam; Tsang, Jessica M; Schwartz, Daniel L; Menon, Vinod

    2012-01-01

    Unlike natural numbers, negative numbers do not have natural physical referents. How does the brain represent such abstract mathematical concepts? Two competing hypotheses regarding representational systems for negative numbers are a rule-based model, in which symbolic rules are applied to negative numbers to translate them into positive numbers when assessing magnitudes, and an expanded magnitude model, in which negative numbers have a distinct magnitude representation. Using an event-related functional magnetic resonance imaging design, we examined brain responses in 22 adults while they performed magnitude comparisons of negative and positive numbers that were quantitatively near (difference 6). Reaction times (RTs) for negative numbers were slower than positive numbers, and both showed a distance effect whereby near pairs took longer to compare. A network of parietal, frontal, and occipital regions were differentially engaged by negative numbers. Specifically, compared to positive numbers, negative number processing resulted in greater activation bilaterally in intraparietal sulcus (IPS), middle frontal gyrus, and inferior lateral occipital cortex. Representational similarity analysis revealed that neural responses in the IPS were more differentiated among positive numbers than among negative numbers, and greater differentiation among negative numbers was associated with faster RTs. Our findings indicate that despite negative numbers engaging the IPS more strongly, the underlying neural representation are less distinct than that of positive numbers. We discuss our findings in the context of the two theoretical models of negative number processing and demonstrate how multivariate approaches can provide novel insights into abstract number representation.

  9. Sensitivity to Referential Ambiguity in Discourse: The Role of Attention, Working Memory, and Verbal Ability

    Science.gov (United States)

    Boudewyn, Megan A.; Long, Debra L.; Traxler, Matthew J.; Lesh, Tyler A.; Dave, Shruti; Mangun, George R.; Carter, Cameron S.; Swaab, Tamara Y.

    2016-01-01

    The establishment of reference is essential to language comprehension. The goal of this study was to examine listeners’ sensitivity to referential ambiguity as a function of individual variation in attention, working memory capacity, and verbal ability. Participants listened to stories in which two entities were introduced that were either very similar (e.g., two oaks) or less similar (e.g., one oak and one elm). The manipulation rendered an anaphor in a subsequent sentence (e.g., oak) ambiguous or unambiguous. EEG was recorded as listeners comprehended the story, after which participants completed tasks to assess working memory, verbal ability, and the ability to use context in task performance. Power in the alpha and theta frequency bands when listeners received critical information about the discourse entities (e.g., oaks) was used to index attention and the involvement of the working memory system in processing the entities. These measures were then used to predict an ERP component that is sensitive to referential ambiguity, the Nref, which was recorded when listeners received the anaphor. Nref amplitude at the anaphor was predicted by alpha power during the earlier critical sentence: Individuals with increased alpha power in ambiguous compared with unambiguous stories were less sensitive to the anaphor's ambiguity. Verbal ability was also predictive of greater sensitivity to referential ambiguity. Finally, increased theta power in the ambiguous compared with unambiguous condition was associated with higher working-memory span. These results highlight the role of attention and working memory in referential processing during listening comprehension. PMID:26401815

  10. Mentoring relationships and the levels of role conflict and role ambiguity experienced by novice nursing faculty.

    Science.gov (United States)

    Specht, Jennifer A

    2013-01-01

    This study explored the effect of mentoring on the levels of role conflict and role ambiguity experienced by novice nursing faculty related to their transitions into academe using a descriptive, comparative design. It also measured the relationship between the quality of mentoring experiences of novice nursing faculty and their levels of role conflict and role ambiguity using a correlational design. P. Benner's (1984) novice to expert model was utilized as a framework for successful role transition. J. R. Rizzo, R. J. House, and S. I. Lirtzman's (1970) role conflict and role ambiguity scale was used to measure the levels of role conflict and role ambiguity experienced by novice nursing faculty. Results indicate that participants (n = 224) who were mentored have significantly lower levels of role conflict (M = 3.57) and role ambiguity (M = 3.02) than those who were not mentored (M = 4.62 and M = 3.90, respectively). Also significant, the higher the participants' reported levels of quality of mentoring experiences were, the lower their levels of role conflict and role ambiguity were. The results of this study indicate that mentoring eases the transition of novice nursing faculty from practice into academe by decreasing the degree of role ambiguity and role conflict that they experience.

  11. The effect of stereotypical primes on the neural processing of racially ambiguous faces.

    Science.gov (United States)

    Dickter, Cheryl L; Kittel, Julie A

    2012-01-01

    Previous research has demonstrated that an early attentional component of the event-related potential (ERP), the P2, is sensitive to the distinction between the processing of racial outgroup and ingroup faces but may not be sensitive to the distinction between racially ambiguous and ingroup faces. Recent behavioral work, however, has suggested that contextual information may affect the processing of racially ambiguous faces. Thus, the first goal of this study was to examine whether the early neural processing of racially ambiguous faces would be affected by primed stereotypes. White college student participants (n = 29) completed a task in which they racially categorized monoracial Black and White faces and racially ambiguous Black-White morphs. These faces were preceded by positive and negative Black and White stereotypical primes. Results indicated that P2 amplitude to the racially ambiguous faces was moderated by the valence of the primes such that negative primes led to greater neural processing of the racially ambiguous faces than positive primes. Furthermore, the extent to which P2 amplitude was affected by prime valence was moderated by individual differences in preference for structure and categorical thinking, as well as comfort with ambiguity.

  12. Monitoring the growth of the neural representations of new animal concepts.

    Science.gov (United States)

    Bauer, Andrew James; Just, Marcel Adam

    2015-08-01

    Although enormous progress has recently been made in identifying the neural representations of individual object concepts, relatively little is known about the growth of a neural knowledge representation as a novel object concept is being learned. In this fMRI study, the growth of the neural representations of eight individual extinct animal concepts was monitored as participants learned two features of each animal, namely its habitat (i.e., a natural dwelling or scene) and its diet or eating habits. Dwelling/scene information and diet/eating-related information have each been shown to activate their own characteristic brain regions. Several converging methods were used here to capture the emergence of the neural representation of a new animal feature within these characteristic, a priori-specified brain regions. These methods include statistically reliable identification (classification) of the eight newly acquired multivoxel patterns, analysis of the neural representational similarity among the newly learned animal concepts, and conventional GLM assessments of the activation in the critical regions. Moreover, the representation of a recently learned feature showed some durability, remaining intact after another feature had been learned. This study provides a foundation for brain research to trace how a new concept makes its way from the words and graphics used to teach it, to a neural representation of that concept in a learner's brain. PMID:26032608

  13. Social Representations of Intelligence

    Directory of Open Access Journals (Sweden)

    Elena Zubieta

    2016-02-01

    Full Text Available The article stresses the relationship between Explicit and Implicit theories of Intelligence. Following the line of common sense epistemology and the theory of Social Representations, a study was carried out in order to analyze naive’s explanations about Intelligence Definitions. Based on Mugny & Carugati (1989 research, a self-administered questionnaire was designed and filled in by 286 subjects. Results are congruent with the main hyphotesis postulated: A general overlap between explicit and implicit theories showed up. According to the results Intelligence appears as both, a social attribute related to social adaptation and as a concept defined in relation with contextual variables similar to expert’s current discourses. Nevertheless, conceptions based on “gifted ideology” still are present stressing the main axes of Intelligence debate: biological and sociological determinism. In the same sense, unfamiliarity and social identity are reaffirmed as organizing principles of social representation. The distance with the object -measured as the belief in intelligence differences as a solve/non solve problem- and the level of implication with the topic -teachers/no teachers- appear as discriminating elements at the moment of supporting specific dimensions. 

  14. Knowledge representation with SOA

    Directory of Open Access Journals (Sweden)

    Daniela Gotseva

    2013-01-01

    Full Text Available This paper addresses the problem of supporting the software development process through the artificial intelligence. The expert systems could advise the Domain Engineer in programming without the detailed experience in programming languages. He will use and integrate, with the help of deductive database and domain knowledge, the previously developed software components to new complex functionalities. The objective of this document is to provide the knowledge representation about atomic Web Services which will be registered as the facts in the deductive database. The author proposes to use the decision rules in decision tables for representing the service model which consists of semantic specification, interface description, service quality (QoS, non-functional properties. Also the use of Domain Specific Languages (DSL for modeling Domain Engineers re-quests to the expert system will be considered within this document. As the illustrative use case for described knowledge representation the author proposes the domain of SOA-based geographic information systems (GIS which represent a new branch of information and communication technologies.

  15. Scene statistics: neural representation of real-world structure in rapid visual perception

    NARCIS (Netherlands)

    I.I.A. Groen

    2014-01-01

    How does the brain represent our visual environment? Research has revealed brain areas that respond to specific information such as faces and objects, but how a representation of an entire visual scene is formed is still unclear. This thesis explores the idea that scene statistics play an important

  16. 模糊决策的认知神经机制%The Cognitive and Neural Mechanism of Ambiguity Decision-making

    Institute of Scientific and Technical Information of China (English)

    张凤华; 张玉婷; 向玲; 胡竹菁

    2015-01-01

    modified IGT task and urn drawing task, and employing ERP and fMRI techniques, we plan to investigate the cognitive and neural mechanism of decision-making under ambiguity; Finally, we will validate the above results from a developmental and clinical perspective. Overall, the findings will help to expand research areas of decision-making under ambiguity, and will provide important theoretical guidance to understand human beings’ decision-making mechanism under ambiguous conditions and clarify the relationship between the decision-making under ambiguity and risk decision- making. At last, the findings have great theoretical and practical values on guiding cognitive diagnosis and therapy for clinical populations such as the addicts and the brain-impaired patients, and on giving insights to the enterprises and the individuals in real decision-making situations.

  17. [The ambiguous concept of predialysis: proposal for a model].

    Science.gov (United States)

    Alberghini, Elena; Gambirasio, Maria Cristina; Sarcina, Cristina; Biazzi, Cecilia; Ferrario, Francesca; Corghi, Enzo; Baragetti, Ivano; Buzzi, Laura; Visciano, Bianca; Terraneo, Veronica; Santagostino, Gaia; Pozzi, Claudio

    2011-01-01

    In 2009, 90% of nephrology centers in Lombardy declared to have a ''predialysis'' outpatient department, without, however, specifying its meaning. Research carried out in 2008 among nephrology centers in Piemonte showed how ambiguous this term was. According to the 2007 EDTA-ERA Registry, about 68% of European nephrology centers stated that they had an outpatient department for stage 4-5 CKD patients, but no information was available about the role of patients in the choice of dialysis. It is known that when the predialysis phase is poorly managed, the patient's rehabilitation will be more difficult. Dissatisfaction with dialysis often leads to withdrawal from dialysis, as several registries have shown. For this reason, we created a predialysis course at our center, involving a nephrologist, a nurse, and a dietician. The nephrologist helps the patient choose the most suitable therapeutic strategy, which means that doctor and patient share the responsibility for the treatment choice. The offered options are hemodialysis, peritoneal dialysis, preemptive kidney transplant, and a conservative dietary-pharmacological program. The nurse plans at least 4 meetings: 1) to talk with the patient in order to get to know him or her and his/her family; 2) to provide information about the dialysis procedure and establish the patient's preferences; 3) to clear any doubts about the treatment and deliver a booklet with information about the chosen dialysis procedure; 4) to explain the chosen dialysis procedure; 5) to meet the patient after their preparation for dialysis (vascular access or peritoneal catheter). The dietician manages the dietary programs both for patients who are close to starting dialysis and those on a longlasting conservative program. The predialysis course includes a meeting among all those involved with the patient (nephrologists, nurses, dieticians) to exchange information with the purpose of shared evaluation and decision-making. PMID:22028269

  18. Processing ambiguous Spanish se in a minimal chain.

    Science.gov (United States)

    Meseguer, Enrique; Acuña-Fariña, Carlos; Carreiras, Manuel

    2009-04-01

    The recovery of pieces of information that are not linguistically expressed is a constant feature of the process of language comprehension. In the processing literature, such missing information is generally referred to as "gaps". Usually, one resolves gaps by finding "fillers" in either the sentence or the context. For instance, in Peter seemed to be upset, Peter is really the subject of being upset but appears as surface subject of seems. Sometimes constituents move, leaving gaps behind. Various Romance languages such as Spanish or Italian have a grammatical particle se/si, which, as it is extremely ambiguous, licenses different sorts of gaps. In Spanish, se can encode at least reflexive, impersonal, and passive meanings. In an eye-tracking experiment we contrast reflexive structures containing postverbal subjects with impersonal structures with no subjects (GAP se vendó apresuradamente el corredor/"the runner bandaged himself hurriedly" vs. GAP se vendó apresuradamente al corridor/"(someone) bandaged the runner hurriedly"). In a second manipulation we contrast the presence of an extra argument with se-passives (GAP se vendó el tobillo el corredor/"the runner bandaged his ankle" vs. GAP se vendó el tobillo al corridor/"the runner's ankle was bandaged"). Our comparisons involve contrasting standard transitive structures with nonstandard word order (postverbal subject and a preverbal subject gap) against inherently complex and less habitual structures such as impersonals (with no subject) or se-passives (with subjects in canonical object position). We evaluate the minimal chain principle (de Vincenzi, 1991), according to which displacement is costly because it entails complex (derivational) "chains" that must be undone before phrasal packaging can commence. We show the minimal chain principle to be essentially correct when contrasting more complex but more frequent structures with less complex but less frequent structures. A noteworthy feature of this research

  19. Multimodal brain visualization

    Science.gov (United States)

    Nadeem, Saad; Kaufman, Arie

    2016-03-01

    Current connectivity diagrams of human brain image data are either overly complex or overly simplistic. In this work we introduce simple yet accurate interactive visual representations of multiple brain image structures and the connectivity among them. We map cortical surfaces extracted from human brain magnetic resonance imaging (MRI) data onto 2D surfaces that preserve shape (angle), extent (area), and spatial (neighborhood) information for 2D (circular disk) and 3D (spherical) mapping, split these surfaces into separate patches, and cluster functional and diffusion tractography MRI connections between pairs of these patches. The resulting visualizations are easier to compute on and more visually intuitive to interact with than the original data, and facilitate simultaneous exploration of multiple data sets, modalities, and statistical maps.

  20. A STUDY OF THE CORRELATION BETWEEN ENGLISH MAJORS' SCORES OF TEM4 AND TOLERANCE OF AMBIGUITY

    Institute of Scientific and Technical Information of China (English)

    ChenWencun

    2004-01-01

    This is a study of the effect of English majors' tolerance ofambiguity on their scores of TEM4. The subjects for the surveyare 193 English major students. Statistical results of the surveyshow that the students' tolerance of ambiguity distributesnormally and their scores of listening comprehension and totalscores are significantly correlated with their tolerance ofambiguity. A weak positive correlation is also found betweentheir scores of dictation, cloze as well as reading comprehensionand tolerance of ambiguity. Students' scores in writing,structure and vocabulary are not significantly correlated withtolerance of ambiguity. The author makes some analysesassociating the results of the investigation with some scholarlyinferences and gives some suggestions on foreign languageteaching.

  1. Decision Lists for Lexical Ambiguity Resolution Application to Accent Restoration in Spanish and French

    CERN Document Server

    Yarowsky, D

    1994-01-01

    This paper presents a statistical decision procedure for lexical ambiguity resolution. The algorithm exploits both local syntactic patterns and more distant collocational evidence, generating an efficient, effective, and highly perspicuous recipe for resolving a given ambiguity. By identifying and utilizing only the single best disambiguating evidence in a target context, the algorithm avoids the problematic complex modeling of statistical dependencies. Although directly applicable to a wide class of ambiguities, the algorithm is described and evaluated in a realistic case study, the problem of restoring missing accents in Spanish and French text.

  2. The Complex Ambiguity Function Based on Downsampled Fourth-Order Statistics

    Institute of Scientific and Technical Information of China (English)

    MAYongfeng; ZHANGWeiqiang; TAORan

    2004-01-01

    Aiming at the problem of target detection in passive radar in correlated noise surroundings, we present a new estimation of the Complex ambiguity function based on Downsampled fourth-order statistics (CAF-DFOS) to improve the performances of the traditional Complex ambiguity function based on Second-order statistics (CAF-SOS) and the existing Complex ambiguity function based on Fourth-order statistics (CAF-FOS). Both the theory and the simulations show that in the aspect of Gaussian noise suppression, its performance is better than the CAF-SOS algorithm; in the aspect of estimate variance and frequency resolution, its performance is better than the CAF-FOS algorithm.

  3. Brain Fingerprinting

    Directory of Open Access Journals (Sweden)

    Ravi Kumar

    2012-12-01

    Full Text Available Brain Fingerprinting is a scientific technique to determine whether or not specific information is stored in an individual's brain by measuring a electrical brain wave response to Word, phrases, or picture that are presented on computer screen. Brain Fingerprinting is a controversial forensic science technique that uses electroencephalography (EEG to determine whether specific information is stored in a subject's brain.

  4. Brain Fingerprinting

    Directory of Open Access Journals (Sweden)

    ravi kumar

    2012-12-01

    Full Text Available Brain Fingerprinting is a scientific technique to determine whether or not specific information is stored in an individual's brain by measuring a electrical brain wave response to Word, phrases, or picture that are presented on computer screen. Brain Fingerprinting is a controversial forensic science technique that uses electroencephalograph y (EEG to determine whether specific information is stored in a subject's brain

  5. Brain Tumors

    Science.gov (United States)

    A brain tumor is a growth of abnormal cells in the tissues of the brain. Brain tumors can be benign, with no cancer cells, ... cancer cells that grow quickly. Some are primary brain tumors, which start in the brain. Others are ...

  6. Shared abstract representation of linguistic structure in bilingual sentence comprehension.

    Science.gov (United States)

    Kidd, Evan; Tennant, Emilie; Nitschke, Sanjo

    2015-08-01

    Although there is strong evidence for shared abstract grammatical structure in bilingual speakers from studies of sentence production, comparable evidence from studies of comprehension is lacking. Twenty-seven (N = 27) English-German bilingual adults participated in a structural priming study where unambiguous English subject and object relative clause (RC) structures were used to prime corresponding subject and object RC interpretations of structurally ambiguous German RCs. The results showed that English object RCs primed significantly greater object RC interpretations in German in comparison to baseline and subject RC prime conditions, but that English subject RC primes did not change the participants' baseline preferences. This is the first study to report abstract crosslinguistic priming in comprehension. The results specifically suggest that word order overlap supports the integration of syntactic structures from different languages in bilingual speakers, and that these shared representations are used in comprehension as well as production.

  7. Image Hierarchical Representations Models based on Latent Dirichlet Allocation

    Directory of Open Access Journals (Sweden)

    Fushun WANG

    2013-08-01

    Full Text Available Existing image layer representations methods are very feed-forward, and then not able to deal with small ambiguities. A probabilistic model is proposed, and it learns and deduces each layer in that hierarchy together. Therefore, we consider a recursive probabilistic decomposition process, and derive a new yielded method based on recursive Latent Dirichlet Allocation. We show 2 significant properties of the novel probabilistic method: 1 pulsing another hierarchical to represent the enhanced results on that smooth method; 2 an entire Bayesian method beats a feed-forward running of the novel method. The method can be evaluated on a criterion recognition dataset. It takes the probability of recursive decomposition process into account, and obtains multilayer structure pyramid LDA derived model through the derivation. Experiments demonstrate that the novel technique beats existing hierarchical approaches, and present better performance

  8. Diagnoses, syndromes, and diseases: a knowledge representation problem.

    Science.gov (United States)

    Calvo, Franz; Karras, Bryant T; Phillips, Richard; Kimball, Ann Marie; Wolf, Fred

    2003-01-01

    Despite their widespread use, the terms "syndrome", "disease" and "diagnosis" are sometimes utilized improperly and ambiguously, compounding the complexities of medical knowledge representation. The definitions and illustrative examples provided here will be useful for developers of diagnostic expert systems. Description of the Problem Representing medical knowledge is a highly complex endeavor. The improper use of the terms "syndrome", "disease" and their relations to "diagnosis" is one of the difficulties with which medical informaticians must deal, especially when developing expert systems to support diagnoses. Although ubiquitous in medical and lay discourse, the term "disease" has no unambiguous, generally accepted definition. How-ever, most of those using this term allow themselves the comfortable delusion that everyone knows what it means. Only sparse and fragmented literature could be found regarding this issue.

  9. Improved Spectral Representation for Birdcall Based on Fractional Fourier Transform

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A novel spectral representation based on fractional Fourier transform (FrFT) is proposed and applied to birdcall analysis. The FrFT-based spectrogram of a signal is derived and compared with its FT-based counterpart, and the spectrum gathering method is used to show the energy distribution related to the pitch frequency. The fixed transform order and adaptive orders for FrFT are tested. The fixed order can be obtained empirically or calculated according to the known chirp rate. The adaptive optimal orders are determined by using ambiguity function. Experimental results with birdcalls show that the FrFT-based spectrogram with an optimal transform order has higher resolution than its STFT-based counterpart, and the better performance can be achieved if adaptive orders are used.

  10. Representation of Musical Computer Processes

    OpenAIRE

    Fober, Dominique; Orlarey, Yann; Letz, Stéphane

    2014-01-01

    International audience The paper presents a study about the representation of musical computer processes within a music score. The idea is to provide performers with information that could be useful especially in the context of interactive music. The paper starts with a characterization of a musical computer process in order to define the values to be represented. Next it proposes an approach to time representation suitable to asynchronous processes representation.

  11. Congruence properties of induced representations

    DEFF Research Database (Denmark)

    Mayer, Dieter; Momeni, Arash; Venkov, Alexei

    In this paper we study representations of the projective modular group induced from the Hecke congruence group of level 4 with Selberg's character. We show that the well known congruence properties of Selberg's character are equivalent to the congruence properties of the induced representations....... Concerning this congruence property, it turns out that working with the induced representations is easier than with Selberg's character itself. We also show that the kernels of the induced representations determine an infinite sequence of noncongruence groups, whose noncongruence property can not be detected...

  12. Integral geometry and representation theory

    CERN Document Server

    Gel'fand, I M; Vilenkin, N Ya

    1966-01-01

    Generalized Functions, Volume 5: Integral Geometry and Representation Theory is devoted to the theory of representations, focusing on the group of two-dimensional complex matrices of determinant one.This book emphasizes that the theory of representations is a good example of the use of algebraic and geometric methods in functional analysis, in which transformations are performed not on the points of a space, but on the functions defined on it. The topics discussed include Radon transform on a real affine space, integral transforms in the complex domain, and representations of the group of comp

  13. Intentionality, Representation, and Anticipation

    Science.gov (United States)

    De Preester, Helena

    2002-09-01

    Both Brentano and Merleau-Ponty have developed an account of intentionality, which nevertheless differ profoundly in the following respect. According to Brentano, intentionality mainly is a matter of mental presentations. This marks the beginning of phenomenology's difficult relation with the nature of the intentional reference. Merleau-Ponty, on the other hand, has situated intentionality on the level of the body, a turn which has important implications for the nature of intentionality. Intentionality no longer is primarily based on having (re)presentations, but is rooted in the dynamics of the living body. To contrast those approaches enables us to make clear in what way intentionality is studied nowadays. On the one hand, intentionality is conceived of as a matter of formal-syntactical causality in cognitive science, and in particular in classical-computational theory. On the other hand, a interactivist approach offers a more Merleau-Ponty-like point of view, in which autonomy, embodiment and interaction are stressed.

  14. Computer aided surface representation

    Energy Technology Data Exchange (ETDEWEB)

    Barnhill, R.E.

    1990-02-19

    The central research problem of this project is the effective representation, computation, and display of surfaces interpolating to information in three or more dimensions. If the given information is located on another surface, then the problem is to construct a surface defined on a surface''. Sometimes properties of an already defined surface are desired, which is geometry processing''. Visualization of multivariate surfaces is possible by means of contouring higher dimensional surfaces. These problems and more are discussed below. The broad sweep from constructive mathematics through computational algorithms to computer graphics illustrations is utilized in this research. The breadth and depth of this research activity makes this research project unique.

  15. Parental representations of transsexuals.

    Science.gov (United States)

    Parker, G; Barr, R

    1982-06-01

    The parental representations of 30 male-to-female transsexuals were rated using a measure of fundamental parental dimensions and shown to be of acceptable validity as a measure both of perceived and actual parental characteristics. Scores on that measure were compared separately against scores returned by matched male and female controls. The transsexuals did not differ from the male controls in their scoring of their mothers but did score their fathers as less caring and more overprotective. These differences were weaker for the comparisons made against the female controls. Item analyses suggested that the greater paternal "overprotection" experienced by transsexuals was due to their fathers being perceived as offering less encouragement to their sons' independence and autonomy. Several interpretations of the findings are considered. PMID:7138296

  16. Robust image analysis with sparse representation on quantized visual features.

    Science.gov (United States)

    Bao, Bing-Kun; Zhu, Guangyu; Shen, Jialie; Yan, Shuicheng

    2013-03-01

    Recent techniques based on sparse representation (SR) have demonstrated promising performance in high-level visual recognition, exemplified by the highly accurate face recognition under occlusion and other sparse corruptions. Most research in this area has focused on classification algorithms using raw image pixels, and very few have been proposed to utilize the quantized visual features, such as the popular bag-of-words feature abstraction. In such cases, besides the inherent quantization errors, ambiguity associated with visual word assignment and misdetection of feature points, due to factors such as visual occlusions and noises, constitutes the major cause of dense corruptions of the quantized representation. The dense corruptions can jeopardize the decision process by distorting the patterns of the sparse reconstruction coefficients. In this paper, we aim to eliminate the corruptions and achieve robust image analysis with SR. Toward this goal, we introduce two transfer processes (ambiguity transfer and mis-detection transfer) to account for the two major sources of corruption as discussed. By reasonably assuming the rarity of the two kinds of distortion processes, we augment the original SR-based reconstruction objective with l(0) norm regularization on the transfer terms to encourage sparsity and, hence, discourage dense distortion/transfer. Computationally, we relax the nonconvex l(0) norm optimization into a convex l(1) norm optimization problem, and employ the accelerated proximal gradient method to optimize the convergence provable updating procedure. Extensive experiments on four benchmark datasets, Caltech-101, Caltech-256, Corel-5k, and CMU pose, illumination, and expression, manifest the necessity of removing the quantization corruptions and the various advantages of the proposed framework.

  17. Ambiguities in strong absorption parametrisations of nuclear scattering data

    International Nuclear Information System (INIS)

    Fixed energy inverse scattering methods have been applied to extract 12C - 208Pb inversion potentials from measured differential cross sections. A semiclassical (WKB) inversion scheme was used to ascertain those complex, local interactions for the data taken at 1449 MeV. The first step was to fit the differential cross section data with a McIntyre form for the S-function. Then each McIntyre S-function was mapped into a rational function representation with which the inversion was performed. The inversion potentials vary significantly in their absorption components within the sensitive radial regions. The results highlight the crucial importance of making more extensive and accurate measurements of cross section data before a much further understanding can be made of heavy ion collisions. 18 refs., 3 tabs., 3 figs

  18. Brain Basics

    Medline Plus

    Full Text Available ... as depression. The Growing Brain Inside the Brain: Neurons & Neural Circuits Neurons are the basic working unit of the brain ... specialized for the function of conducting messages. A neuron has three basic parts: Cell body which includes ...

  19. Brain surgery

    Science.gov (United States)

    Craniotomy; Surgery - brain; Neurosurgery; Craniectomy; Stereotactic craniotomy; Stereotactic brain biopsy; Endoscopic craniotomy ... cut depends on where the problem in the brain is located. The surgeon creates a hole in ...

  20. Brain Malformations

    Science.gov (United States)

    Most brain malformations begin long before a baby is born. Something damages the developing nervous system or causes it ... medicines, infections, or radiation during pregnancy interferes with brain development. Parts of the brain may be missing, ...

  1. Brain Basics

    Medline Plus

    Full Text Available ... Brain Basics provides information on how the brain works, how mental illnesses are disorders of the brain, ... others live with symptoms of mental illness every day. They can be moderate, or serious and cause ...

  2. Brain Basics

    Medline Plus

    Full Text Available ... The Growing Brain Inside the Brain: Neurons & Neural Circuits Neurons are the basic working unit of the ... distant nerve cells (via axons) to form brain circuits. These circuits control specific body functions such as ...

  3. Brain Basics

    Medline Plus

    Full Text Available ... Basics will introduce you to some of this science, such as: How the brain develops How genes and the environment affect the brain The basic structure of the brain How different parts of ...

  4. Brain Basics

    Medline Plus

    Full Text Available ... science, such as: How the brain develops How genes and the environment affect the brain The basic ... that with brain development in people mental disorders. Genes and environmental cues both help to direct this ...

  5. PRF-ambiguity resolution for SAR by contrast minimization in range-Doppler domain

    Institute of Scientific and Technical Information of China (English)

    YU Mingcheng; XU Jia; PENG Yingning

    2007-01-01

    An algorithm was developed to accurately estimate the Doppler centroid,which is needed for high-quality synthetic aperture radar(SAR)image formation by resolving the SAR pulse repetition frequency(PRF)ambiguity.The algorithm uses the SAR range migration to resolve the PRF-ambiguity by searching for a PRF-ambiguity number that minimizes the intensity contrast in the range-Doppler domain.Experimental results show that the approach.compared with traditional methods for resolving the SAR PRF ambiguity,is more suitable for both high contrast scenes such as urban areas and low contrast scenes such as mountains.Moreover,the approach is more computationally efficient for there are no time-consuming correlations or fast Fourier transform(FFT)operations needed in the range-Doppler domain and only part of the range cells are used in the calculation.

  6. A Test of Rank-Dependent Utility in the Context of Ambiguity

    NARCIS (Netherlands)

    P.P. Wakker; H. Fennema

    1996-01-01

    Experimental investigations of nonexpected utility have primarily concentrated on decision under risk ("probability triangles"). The literature suggests, however, that ambiguity is one of the main causes for deviations from expected utility. This paper investigates the descriptive performance of ran

  7. From Ambiguity Aversion to a Generalized Expected Utility. Modeling Preferences in a Quantum Probabilistic Framework

    CERN Document Server

    Aerts, Diederik

    2015-01-01

    Ambiguity and ambiguity aversion have been widely studied in decision theory and economics both at a theoretical and an experimental level. After Ellsberg's seminal studies challenging subjective expected utility theory (SEUT), several (mainly normative) approaches have been put forward to reproduce ambiguity aversion and Ellsberg-type preferences. However, Machina and other authors have pointed out some fundamental difficulties of these generalizations of SEUT to cope with some variants of Ellsberg's thought experiments, which has recently been experimentally confirmed. Starting from our quantum modeling approach to human cognition, we develop here a general probabilistic framework to model human decisions under uncertainty. We show that our quantum theoretical model faithfully represents different sets of data collected on both the Ellsberg and the Machina paradox situations, and is flexible enough to describe different subjective attitudes with respect to ambiguity. Our approach opens the way toward a quan...

  8. Games of mirrors and ambiguous fictions. The unheimliche in Italian Realismo magico

    OpenAIRE

    Pierluca Nardoni

    2015-01-01

    The paper focuses on some problems of Italian Realismo magico analyzed by means of Sigmund Freud’s Das Unheimliche, particularly through the topics of mirrors, déjà-vu and ambiguity between fiction and reality.

  9. Facilitated lexical ambiguity processing by transcranial direct current stimulation over the left inferior frontal cortex.

    Science.gov (United States)

    Ihara, Aya S; Mimura, Takanori; Soshi, Takahiro; Yorifuji, Shiro; Hirata, Masayuki; Goto, Tetsu; Yoshinime, Toshiki; Umehara, Hiroaki; Fujimaki, Norio

    2015-01-01

    Previous studies suggest that the left inferior frontal cortex is involved in the resolution of lexical ambiguities for language comprehension. In this study, we hypothesized that processing of lexical ambiguities is improved when the excitability of the left inferior frontal cortex is enhanced. To test the hypothesis, we conducted an experiment with transcranial direct current stimulation (tDCS). We investigated the effect of anodal tDCS over the left inferior frontal cortex on behavioral indexes for semantic judgment on lexically ambiguous and unambiguous words within a context. Supporting the hypothesis, the RT was shorter in the anodal tDCS session than in the sham session for ambiguous words. The results suggest that controlled semantic retrieval and contextual selection were facilitated by anodal tDCS over the left inferior frontal cortex. PMID:25208744

  10. Angry-happy interpretations of ambiguous faces in social anxiety disorder.

    Science.gov (United States)

    Maoz, Keren; Eldar, Sharon; Stoddard, Joel; Pine, Daniel S; Leibenluft, Ellen; Bar-Haim, Yair

    2016-07-30

    Social Anxiety Disorder (SAD) is characterized by a tendency to interpret ambiguous social cues as negative. Here we tested whether interpretation of ambiguous faces differs between participants with SAD and non-anxious controls. Twenty-seven individuals with SAD and 21 non-anxious control participants completed an emotion recognition task in which they judged ambiguous morphed faces as happy or angry. Participants with SAD judged a higher proportion of the faces as angry compared to non-anxious participants, and were slower to judge faces as angry compared to happy, while no such reaction time bias manifested in the control group. Finally, happy judgments were slower in the SAD group compared to the control group, while angry judgments were faster in the SAD group compared to the control group. These findings provide evidence for a negative bias in resolving emotional ambiguity in facial expressions among individuals with SAD. PMID:27173656

  11. Four-dimensional aether-like Lorentz-breaking QED revisited and problem of ambiguities

    Energy Technology Data Exchange (ETDEWEB)

    Baeta Scarpelli, A.P. [Setor Tecnico-Cientifico, Departamento de Policia Federal, Rua Hugo D' Antola, 95, Lapa, Sao Paulo (Brazil); Mariz, T. [Universidade Federal de Alagoas, Instituto de Fisica, Maceio, Alagoas (Brazil); Nascimento, J.R.; Petrov, A.Yu. [Universidade Federal da Paraiba, Departamento de Fisica, Caixa Postal 5008, Joao Pessoa, Paraiba (Brazil)

    2013-08-15

    In this paper, we consider the perturbative generation of the CPT-even aether-like Lorentz-breaking term in the extended Lorentz-breaking QED within different approaches and discuss its ambiguities. (orig.)

  12. A Quick Method of Phase Ambiguity Resolution with X-Ray Pulsar Navigation

    Directory of Open Access Journals (Sweden)

    Xuerui Li

    2012-09-01

    Full Text Available In this study, we proposes a quick resolution method based on space search method which is based on least square method, space search method and ambiguity covariance method. The results of simulation indicate that this method can effectively improve the speed and efficiency of phase ambiguity resolution and has some certain reference value to the researches which is related to X-ray pulsar navigation.

  13. Role Satisfaction Mediates the Relation between Role Ambiguity and Social Loafing among Elite Women Handball Players

    OpenAIRE

    Hoigaard, Rune; Fuglestad, Susanne; Peters, Derek M.; De Cuyper, Bert; De Backer, Maarten; Boen, Filip

    2010-01-01

    The aims of the study were to develop a questionnaire on self-reported social loafing (SRSLQ), and then to examine its relations with role ambiguity and role satisfaction in a sample of 110 women handball players competing at the elite level in Norway. Structural equation modeling analyses indicated that the SRSLQ was a psychometrically sound measure. In line with the expectations, role satisfaction fully mediated the positive relation between role ambiguity and self-reported s...

  14. Role Conflict and Role Ambiguity of Chief Executive Officers in International Joint Ventures

    OpenAIRE

    Oded Shenkar; Yoram Zeira

    1992-01-01

    This study examines the organizational and personal correlates of role conflict and role ambiguity of chief executive officers heading international joint ventures. Role conflict was found to be lower when the number of parent firms was higher and when the CEO had spent more years with the organization. Role ambiguity was found to be lower when the CEO had more years of education, when the Power Distance and Masculinity/Femininity gap between parents were lower, and when the Individualism/Col...

  15. Market Shaping as an Answer to Ambiguities. : The Case of Credit Derivatives

    OpenAIRE

    Huault, Isabelle; Rainelli-Le Montagner, Hélène

    2009-01-01

    International audience Building on Smith (1989), we describe the social processes surrounding a new financial OTC derivatives market, the market for credit derivatives. We show that in contradiction with more traditional derivatives, credit derivatives generate ambiguities of a cognitive and political nature. By conducting an in-depth longitudinal qualitative study from 1996 to 2004, we document the efforts made by the promoters of the market to alleviate these ambiguities and show how the...

  16. Resolving the Theoretical Ambiguities of Social Exclusion with reference to Polarisation and Conflict

    OpenAIRE

    Fischer, Andrew Martín

    2008-01-01

    textabstractAbstract This paper addresses several ambiguities in the social exclusion literature that fuel the common criticism that the concept is redundant with respect to already existing poverty approaches, particularly more multidimensional and processual approaches such as relative or capability deprivation. It is argued that these ambiguities arise from the fact that social exclusion is generally not differentiated from poverty, even though it is widely acknowledged that social exclusi...

  17. Ionosphere influence on success rate of GPS ambiguity resolution in a satellite formation flying

    Science.gov (United States)

    Baroni, Leandro

    2015-10-01

    Satellite formation flying is one of the most promising technologies for future space missions. The distribution of sensors and payloads among different satellites provides more redundancy, flexibility, improved communication coverage, among other advantages. One of the fundamental issues in spacecraft formation flying is precise position and velocity determination between satellites. For missions in low Earth orbits, GPS system can meet the precision requirement in relative positioning, since the satellite dynamics is modeled properly. The key for high accuracy GPS relative positioning is to resolve the ambiguities to their integer values. Ambiguities resolved successfully can improve the positioning accuracy to decimetre or even millimetre-level. So, integer carrier phase ambiguity resolution is often a prerequisite for high precision GPS positioning. The determination of relative position was made using an extended Kalman filter. The filter must take into account imperfections in dynamic modeling of perturbations affecting the orbital flight, and changes in solar activity that affects the GPS signal propagation, for mitigating these effects on relative positioning accuracy. Thus, this work aims to evaluate the impact of ionosphere variation, caused by changes in solar activity, in success rate of ambiguity resolution. Using the Ambiguity Dilution of Precision (ADOP) concept, the ambiguity success rate is analyzed and the expected precision of the ambiguity-fixed solution is calculated. Evaluations were performed using actual data from GRACE mission and analyzed for their performance in real scenarios. Analyses were conducted in different configurations of relative position and during different levels of solar activity. Results bring the impact of various disturbances and modeling of solar activity level on the success rate of ambiguity resolution.

  18. The Inertial Attitude Augmentation for Ambiguity Resolution in SF/SE-GNSS Attitude Determination

    OpenAIRE

    Jiancheng Zhu; Xiaoping Hu; Jingyu Zhang; Tao Li; Jinling Wang; Meiping Wu

    2014-01-01

    The Unaided Single Frequency/Single Epoch Global Navigation Satellite System (SF/SE GNSS) model is the most challenging scenario for ambiguity resolution in the GNSS attitude determination application. To improve the performance of SF/SE-GNSS ambiguity resolution without excessive cost, the Micro-Electro-Mechanical System Inertial Measurement Unit (MEMS-IMU) is a proper choice for the auxiliary sensor that carries out the inertial attitude augmentation. Firstly, based on the SF/SE-GNSS compas...

  19. Sexual Self-Concept Ambiguity and the Interpersonal Theory of Suicide Risk

    OpenAIRE

    Talley, Amelia E.; Brown, Sarah L.; Cukrowicz, Kelly; Bagge, Courtney L.

    2015-01-01

    Mechanisms (i.e., thwarted belongingness, perceived burdensomeness, hopelessness) derived from the interpersonal theory of suicide which are hypothesized to account for the relation between sexual orientation self-concept ambiguity and active suicide ideation were examined. Participants included 349 women, among whom 42% currently self-ascribed a non-exclusively heterosexual sexual identity. Among women reporting higher levels of sexual self-concept ambiguity, greater risk for active suicide ...

  20. Roles of frontal and temporal regions in reinterpreting semantically ambiguous sentences

    OpenAIRE

    Vitello, Sylvia; Warren, Jane E; Devlin, Joseph T.; Rodd, Jennifer M.

    2014-01-01

    Semantic ambiguity resolution is an essential and frequent part of speech comprehension because many words map onto multiple meanings (e.g., “bark,” “bank”). Neuroimaging research highlights the importance of the left inferior frontal gyrus (LIFG) and the left posterior temporal cortex in this process but the roles they serve in ambiguity resolution are uncertain. One possibility is that both regions are engaged in the processes of semantic reinterpretation that follows incorrect interpretati...

  1. Roles of frontal and temporal regions in reinterpreting semantically ambiguous sentences

    OpenAIRE

    Sylvia Vitello; Warren, Jane E

    2014-01-01

    Semantic ambiguity resolution is an essential and frequent part of speech comprehension because many words map onto multiple meanings (e.g., “bark”, “bank”). Neuroimaging research highlights the importance of the left inferior frontal gyrus (LIFG) and the left posterior temporal cortex in this process but the roles they serve in ambiguity resolution are uncertain. One possibility is that both regions are engaged in the processes of semantic reinterpretation that follows incorrect interpretati...

  2. Understanding ambiguous words in sentence contexts: Electrophysiological evidence for delayed contextual selection in Broca's aphasia

    OpenAIRE

    Swaab, T.; Brown, C.; Hagoort, P.

    1998-01-01

    This study investigates whether spoken sentence comprehension deficits in Broca's aphasics results from their inability to access the subordinate meaning of ambiguous words (e.g. bank), or alternatively, from a delay in their selection of the contextually appropriate meaning. Twelve Broca's aphasics and twelve elderly controls were presented with lexical ambiguities in three context conditions, each followed by the same target words. In the concordant condition, the sentence context biased th...

  3. LIFG-based attentional control and the resolution of lexical ambiguities in sentence context

    OpenAIRE

    L. Vuong; MARTIN,R

    2010-01-01

    The role of attentional control in lexical ambiguity resolution was examined in two patients with damage to the left inferior frontal gyrus (LIFG) and one control patient with non-LIFG damage. Experiment 1 confirmed that the LIFG patients had attentional control deficits compared to normal controls while the non-LIFG patient was relatively unimpaired. Experiment 2 showed that all three patients did as well as normal controls in using biasing sentence context to resolve lexical ambiguities inv...

  4. Understanding words in sentence contexts: The time course of ambiguity resolution

    OpenAIRE

    Swaab, T.; Brown, C.; Hagoort, P.

    2003-01-01

    Spoken language comprehension requires rapid integration of information from multiple linguistic sources. In the present study we addressed the temporal aspects of this integration process by focusing on the time course of the selection of the appropriate meaning of lexical ambiguities (“bank”) in sentence contexts. Successful selection of the contextually appropriate meaning of the ambiguous word is dependent upon the rapid binding of the contextual information in the sentence to the appropr...

  5. The kindergarten-path effect revisited: children’s use of context in processing structural ambiguities

    OpenAIRE

    Weighall, A. R.

    2007-01-01

    Research with adults has shown that ambiguous spoken sentences are resolved efficiently, exploiting multiple cues—including referential context—to select the intended meaning. Paradoxically, children appear to be insensitive to referential cues when resolving ambiguous sentences, relying instead on statistical properties intrinsic to the language such as verb biases. The possibility that children’s insensitivity to referential context may be an artifact of the experimental design used in prev...

  6. The Role of Informative and Ambiguous Feedback in Avoidance Behavior: Empirical and Computational Findings

    OpenAIRE

    Ahmed A. Moustafa; Jony Sheynin; Myers, Catherine E.

    2015-01-01

    Avoidance behavior is a critical component of many psychiatric disorders, and as such, it is important to understand how avoidance behavior arises, and whether it can be modified. In this study, we used empirical and computational methods to assess the role of informational feedback and ambiguous outcome in avoidance behavior. We adapted a computer-based probabilistic classification learning task, which includes positive, negative and no-feedback outcomes; the latter outcome is ambiguous as i...

  7. Why clowns taste funny: the relationship between humor and semantic ambiguity.

    Science.gov (United States)

    Bekinschtein, Tristan A; Davis, Matthew H; Rodd, Jennifer M; Owen, Adrian M

    2011-06-29

    What makes us laugh? One crucial component of many jokes is the disambiguation of words with multiple meanings. In this functional MRI study of normal participants, the neural mechanisms that underlie our experience of getting a joke that depends on the resolution of semantically ambiguous words were explored. Jokes that contained ambiguous words were compared with sentences that contained ambiguous words but were not funny, as well as to matched verbal jokes that did not depend on semantic ambiguity. The results confirm that both the left inferior temporal gyrus and left inferior frontal gyrus are involved in processing the semantic aspects of language comprehension, while a more widespread network that includes both of these regions and the temporoparietal junction bilaterally is involved in processing humorous verbal jokes when compared with matched nonhumorous material. In addition, hearing jokes was associated with increased activity in a network of subcortical regions, including the amygdala, the ventral striatum, and the midbrain, that have been implicated in experiencing positive reward. Moreover, activity in these regions correlated with the subjective ratings of funniness of the presented material. These results allow a more precise account of how the neural and cognitive processes that are involved in ambiguity resolution contribute to the appreciation of jokes that depend on semantic ambiguity. PMID:21715632

  8. A study of potential sources of linguistic ambiguity in written work instructions.

    Energy Technology Data Exchange (ETDEWEB)

    Matzen, Laura E.

    2009-11-01

    This report describes the results of a small experimental study that investigated potential sources of ambiguity in written work instructions (WIs). The English language can be highly ambiguous because words with different meanings can share the same spelling. Previous studies in the nuclear weapons complex have shown that ambiguous WIs can lead to human error, which is a major cause for concern. To study possible sources of ambiguity in WIs, we determined which of the recommended action verbs in the DOE and BWXT writer's manuals have numerous meanings to their intended audience, making them potentially ambiguous. We used cognitive psychology techniques to conduct a survey in which technicians who use WIs in their jobs indicated the first meaning that came to mind for each of the words. Although the findings of this study are limited by the small number of respondents, we identified words that had many different meanings even within this limited sample. WI writers should pay particular attention to these words and to their most frequent meanings so that they can avoid ambiguity in their writing.

  9. Mediating Effect of Role Ambiguity on Communication Climate: A Meta Analysis

    Directory of Open Access Journals (Sweden)

    Nasser S. Al-Kahtani

    2015-05-01

    Full Text Available The current investigation was an attempt to explore the relationship and contribution of supportive and defensive communication climate with role ambiguity amongst subordinate staff of Salman bin Abdulaziz University, Kingdom of Saudi Arabia. The total questionnaires included in the study were 368 subordinate staff working in different divisions in the university. Communication climate inventory and role ambiguity scale were used to explore the experiences of subordinate staff. The data were analyzed by means of Pearson’s product-moment correlation and step wise multiple regression. The results appeared that (i strategy one of the facet of defensive communication climate were showed inverse significant relationship with role ambiguity, (ii strategy and control facets of defensive communication climate were emerged most dominant predictors of role ambiguity, (iii supportive communication climate and their dimensions were found positive significant relationship with role ambiguity and (iv total supportive communication climate revealed as one of the most significant predictor of role ambiguity. Implication of this investigation and suggestions for future research were discussed to add value in the current areas of knowledge.

  10. Role ambiguity and role conflict among employees in a provincial public hospital

    Directory of Open Access Journals (Sweden)

    Sofia Tsiriga

    2012-04-01

    Full Text Available Health professionals' role ambiguity and role conflict jeopardize the functionality and efficiency of hospitals. Aim: Documentation and exploration of the role conflict and role ambiguity experienced by employees in a Greek provincial public hospital. Material and methods: One hundred four employees aged 22-53 years old. Doctors, nurses technical and administrative personnel working in a provincial public hospital were enrolled in the study. This survey took place in July 2010. The Rizzo's et al role conflict and role ambiguity scales adopted in Greek were used. Scoring is based on a seven point Likert scale. Statistical significance level was set at p<0.05. Analysis was performed with SPSS 17.0. Results: Role conflict and ambiguity score was (4.10± 1.17 and 2.63 ± 1.29 respectively. Regarding role ambiguity, statistically significant differences were observed between employees aged 22-32 yrs old and employees aged 47-53 yrs old (p=0.05. No statistically significant differences were observed regarding role conflict. Conclusions: Role conflict and role ambiguity exist among hospital employees. The present study emphasizes critical issues, with considerable consequences threatening the viability and the efficiency of the health care system.

  11. The inertial attitude augmentation for ambiguity resolution in SF/SE-GNSS attitude determination.

    Science.gov (United States)

    Zhu, Jiancheng; Hu, Xiaoping; Zhang, Jingyu; Li, Tao; Wang, Jinling; Wu, Meiping

    2014-06-26

    The Unaided Single Frequency/Single Epoch Global Navigation Satellite System (SF/SE GNSS) model is the most challenging scenario for ambiguity resolution in the GNSS attitude determination application. To improve the performance of SF/SE-GNSS ambiguity resolution without excessive cost, the Micro-Electro-Mechanical System Inertial Measurement Unit (MEMS-IMU) is a proper choice for the auxiliary sensor that carries out the inertial attitude augmentation. Firstly, based on the SF/SE-GNSS compass model, the Inertial Derived Baseline Vector (IDBV) is defined to connect the MEMS-IMU attitude measurement with the SF/SE-GNSS ambiguity search space, and the mechanism of inertial attitude augmentation is revealed from the perspective of geometry. Then, through the quantitative description of model strength by Ambiguity Dilution of Precision (ADOP), two ADOPs are specified for the unaided SF/SE-GNSS compass model and its inertial attitude augmentation counterparts, respectively, and a sufficient condition is proposed for augmenting the SF/SE-GNSS model strength with inertial attitude measurement. Finally, in the framework of an integer aperture estimator with fixed failure rate, the performance of SF/SE-GNSS ambiguity resolution with inertial attitude augmentation is analyzed when the model strength is varying from strong to weak. The simulation results show that, in the SF/SE-GNSS attitude determination application, MEMS-IMU can satisfy the requirements of ambiguity resolution with inertial attitude augmentation.

  12. Ambiguity: A new way of thinking about responses to climate change.

    Science.gov (United States)

    Fleming, A; Howden, S M

    2016-11-15

    Diversity, interdisciplinarity and transdisciplinarity are now recognized as vital to tackling wicked problems such as those presented by a changing climate (Nature editorial 2015, Ledford 2015; Dick et al., 2016). Including diverse disciplines in science projects enables a range of different views which often facilitate the creation of innovative solutions. Supporting multiple views and options requires a different way of working beyond traditional reductionist approaches to science, communication and decision-making. To embrace diversity in scientific project teams in order to tackle complex, integrated and urgent issues but to expect singular and linear pathways forward is paradoxical. Much has been written about the need for the scientific community to embrace uncertainty (e.g. Popper, Lempert & Bankes 2005; Lempert et al., 2004; Nelson, Howden & Hayman 2013; Bammer & Smithson 2008). We argue that this in itself will not suffice, and that there is also a need to embrace ambiguity in certain situations. Thus, in this article we explore: (1) what ambiguity is, including the benefits it can offer to climate adaptation in particular, using existing approaches to ambiguity in the arts and humanities as examples (2), we discuss practical meanings of ambiguity in relation to climate change, (3) we propose possible next steps for bringing ambiguity into interdisciplinary practice, and (4) we identify some challenges and necessary preconditions to successfully and appropriately embracing ambiguity. PMID:27486065

  13. Non-ambiguity of blind watermarking: a revisit with analytical resolution

    Institute of Scientific and Technical Information of China (English)

    KANG XianGui; HUANG JiWu; ZENG WenJun; SHI Yun Q.

    2009-01-01

    Resistance to ambiguity attack is an important requirement for a secure digital rights management (DRM) system. In this paper, we revisit the non-ambiguity of a blind watermarking based on the compu-tational indistinguishability between pseudo random sequence generator (PRSG) sequence ensemble and truly random sequence ensemble. Ambiguity attacker on a watermarking scheme, which uses a PRSG sequence as watermark, is viewed as an attacker who tries to attack a noisy PRSG sequence. We propose and prove the security theorem for binary noisy PRSG sequence and security theorem for gen-(α is a normalized detection threshold; n is the length of a PRSG sequence) and n≥1.39×m/a2 (mis the key length), the success probability of an ambiguity attack and the missed detection probability can both be made negligibly small thus non-ambiguity and robustness can be achieved simultaneously for both practical quantization-based and blind spread spectrum (SS) watermarking schemes. These analytical resolutions may be used in designing practical non-invertible watermarking schemes and measuring the non-ambiguity of the schemes.

  14. Ambiguity: A new way of thinking about responses to climate change.

    Science.gov (United States)

    Fleming, A; Howden, S M

    2016-11-15

    Diversity, interdisciplinarity and transdisciplinarity are now recognized as vital to tackling wicked problems such as those presented by a changing climate (Nature editorial 2015, Ledford 2015; Dick et al., 2016). Including diverse disciplines in science projects enables a range of different views which often facilitate the creation of innovative solutions. Supporting multiple views and options requires a different way of working beyond traditional reductionist approaches to science, communication and decision-making. To embrace diversity in scientific project teams in order to tackle complex, integrated and urgent issues but to expect singular and linear pathways forward is paradoxical. Much has been written about the need for the scientific community to embrace uncertainty (e.g. Popper, Lempert & Bankes 2005; Lempert et al., 2004; Nelson, Howden & Hayman 2013; Bammer & Smithson 2008). We argue that this in itself will not suffice, and that there is also a need to embrace ambiguity in certain situations. Thus, in this article we explore: (1) what ambiguity is, including the benefits it can offer to climate adaptation in particular, using existing approaches to ambiguity in the arts and humanities as examples (2), we discuss practical meanings of ambiguity in relation to climate change, (3) we propose possible next steps for bringing ambiguity into interdisciplinary practice, and (4) we identify some challenges and necessary preconditions to successfully and appropriately embracing ambiguity.

  15. Ambiguity in English Humor%英语笑话的歧义分析

    Institute of Scientific and Technical Information of China (English)

    温美霞

    2015-01-01

    The linguistic ambiguity,which can be taken as a communication barrier in actual exchanges,is often employed in the realization of jokes to display humorous effect.This paper tentatively explores the inference and appreciation of English jokes from three perspectives,including phonological ambiguity,lexical ambiguity and syntactic ambiguity to illuminate the fact that linguistic ambiguity is an important mechanism for the birth of humors and that humor can be understood effectively with the help of the analysis of ambiguity.%歧义在正常交际中可被视为交际的障碍,然而运用到笑话中却能产生幽默诙谐的效果。本文根据触发歧义的语言层次,试从语音歧义,词汇歧义和句法歧义三方面理解和欣赏英语笑话,表明歧义机制是建构幽默的重要手段,通过分析歧义能有效解读幽默。

  16. Effect of Changing Governance System: Result of Western Style Management Adoption to Japanese Culture of Ambiguity

    Directory of Open Access Journals (Sweden)

    Kohichiro Hotta

    2009-02-01

    Full Text Available This paper considers the difficulty of management style change through observation of the management style of Company-A, one of the biggest Japanese IT companies. Japanese economy grew after World War II until the early 1990's. During that era, Ba or SECI process worked in Japanese organizations very well. Further, there was an ambiguous culture in the background of such characteristics. Some kinds of ambiguity or adhocracy made positive effects for Japanese organizational activity, or ambiguity played an important role for Ba activity. There were nested Ba's in each organization with ambiguity. Ambiguous descriptions of roles for each organizational unit activated nested Ba's and generated hot groups. After the economic crisis, Company-A changed its governance and gave clear targets for each organizational unit and for each employee. This change gave new difficulty and diminishes its competence. The change denied the ambiguity in the organization but it was the basis of the competence. Adopting a new system of governance is not a simple activity. Systems must be adjusted to the culture of the organization. Company-A should study competitors in different cultures and adjust the methodology for its culture.

  17. Representational neglect for words as revealed by bisection tasks.

    Science.gov (United States)

    Arduino, Lisa S; Marinelli, Chiara Valeria; Pasotti, Fabrizio; Ferrè, Elisa Raffaella; Bottini, Gabriella

    2012-03-01

    In the present study, we showed that a representational disorder for words can dissociate from both representational neglect for objects and neglect dyslexia. This study involved 14 brain-damaged patients with left unilateral spatial neglect and a group of normal subjects. Patients were divided into four groups based on presence of left neglect dyslexia and representational neglect for non-verbal material, as evaluated by the Clock Drawing test. The patients were presented with bisection tasks for words and lines. The word bisection tasks (with words of five and seven letters) comprised the following: (1) representational bisection: the experimenter pronounced a word and then asked the patient to name the letter in the middle position; (2) visual bisection: same as (1) with stimuli presented visually; and (3) motor bisection: the patient was asked to cross out the letter in the middle position. The standard line bisection task was presented using lines of different length. Consistent with the literature, long lines were bisected to the right and short lines, rendered comparable in length to the words of the word bisection test, deviated to the left (crossover effect). Both patients and controls showed the same leftward bias on words in the visual and motor bisection conditions. A significant difference emerged between the groups only in the case of the representational bisection task, whereas the group exhibiting neglect dyslexia associated with representational neglect for objects showed a significant rightward bias, while the other three patient groups and the controls showed a leftward bisection bias. Neither the presence of neglect alone nor the presence of visual neglect dyslexia was sufficient to produce a specific disorder in mental imagery. These results demonstrate a specific representational neglect for words independent of both representational neglect and neglect dyslexia.

  18. Adjoint Functors and Representation Dimensions

    Institute of Scientific and Technical Information of China (English)

    Chang Chang XI

    2006-01-01

    We study the global dimensions of the coherent functors over two categories that are linked by a pair of adjoint functors. This idea is then exploited to compare the representation dimensions of two algebras. In particular, we show that if an Artin algebra is switched from the other, then they have the same representation dimension.

  19. Quantum operations in probabilistic representation

    Energy Technology Data Exchange (ETDEWEB)

    Karpati, A; Adam, P; Janszky, J [Research Institute for Solid State Physics and Optics, Hungarian Academy of Sciences, Budapest (Hungary)], E-mail: adam@szfki.hu

    2009-07-15

    Representing a single qubit by using a set of totally decohered mixed-state qubits is considered. A representation is constructed where physically realizable quantum mechanical transformations correspond approximately to unitary operations on the qubit. It is shown that the representation is valid for multiple qubit systems as well, and the precision of the approximation is sufficient for the realization of quantum algorithms.

  20. Deconfinement of higher representation sources

    International Nuclear Information System (INIS)

    At the finite-temperature phase transition of non-abelian gauge theories static quarks, external sources in the fundamental representation of the gauge group, are deconfined. We discuss the behavior of 'quark' sources in higher representations of the gauge group around this deconfinement phase transition. (orig.)