901 resultados para Normative reasoning
Resumo:
We have attempted to establish normative values of components of the magnetic evoked field to flash and pattern reversal stimuli prior to clinical use of the MEG. Full visual field, binocular evoked magnetic fields were recorded from 100 subjects 16 to 86 years of age with a single channel dc Squid (BTI) second-order gradiometer at a point 5-6cm above the inion. The majority of subjects showed a large positive component (out going magnetic field) of mean latency 115 ms (SD range 2.5 -11.8 in different decades of life) to the pattern reversal stimulus. In many subjects, this P100M was preceeded and succeeded by negative deflections (in going field). About 6% of subjects showed an inverted response i.e. a PNP wave. Waveforms to flash were more variable in shape with several positive components; the most consistent having a mean latency of 110ms (SD range 6.4-23.2). Responses to both stimuli were consistent when measured on the same subject on six different occasions (SD range 4.8 to 7.3). The data suggest that norms can be established for evoked magnetic field components, in particular for the pattern reversal P100M, which could be used in the diagnosis of neuro-opthalmological disease.
Resumo:
The practicality or recording normative data for two components of the visually evoked magnetic response (VEMR) (P100M and P2M) using a single channel dc-SQUID second order gradiometer in an unshielded environment was investigated. Latency norms of the P100M and P2M were more variable than the corresponding electrical P100 and P2 visual evoked potentials. Methods of improving the normative data for clinical use were discussed.
Resumo:
Qualitative reasoning has traditionally been applied in the domain of physical systems, where there are well established and understood laws governing the behaviour of each `component' in the system. Such application has shown that it is possible to produce models which can be used for explaining and predicting the behaviour of physical phenomena and also trouble-shooting. The principles underlying the theory ensure that the models are robust and exhibit consistent behaviour under all conditions. This research examines the validity of applying the theory in the financial domain where such laws may not exist or if they do, may not be universally applicable. In particular, it investigates how far these principles and techniques may be applied in the construction of financial analysis models. Because of the inherent differences in the nature of these two domains, it is argued that a different qualitative value system ought to be employed. The dissertation enlarges on the constraints this places on model descriptions and the effect it may have on the power and usefulness of the resulting models. It also describes the implementation of a system that investigates the implications of applying this theory by way of testing it on situations drawn from both text-books and published financial information.
Resumo:
Knitwear design is a creative activity that is hard to automate using the computer. The production of the associated knitting pattern, however, is repetitive, time-consuming and error-prone, calling for automation. Our objectives are two-fold: to facilitate the design and to ease the burden of calculations and checks in pattern production. We conduct a feasibility study for applying case-based reasoning in knitwear design: we describe appropriate methods and show their application.
Resumo:
This thesis presents an investigation into the application of methods of uncertain reasoning to the biological classification of river water quality. Existing biological methods for reporting river water quality are critically evaluated, and the adoption of a discrete biological classification scheme advocated. Reasoning methods for managing uncertainty are explained, in which the Bayesian and Dempster-Shafer calculi are cited as primary numerical schemes. Elicitation of qualitative knowledge on benthic invertebrates is described. The specificity of benthic response to changes in water quality leads to the adoption of a sensor model of data interpretation, in which a reference set of taxa provide probabilistic support for the biological classes. The significance of sensor states, including that of absence, is shown. Novel techniques of directly eliciting the required uncertainty measures are presented. Bayesian and Dempster-Shafer calculi were used to combine the evidence provided by the sensors. The performance of these automatic classifiers was compared with the expert's own discrete classification of sampled sites. Variations of sensor data weighting, combination order and belief representation were examined for their effect on classification performance. The behaviour of the calculi under evidential conflict and alternative combination rules was investigated. Small variations in evidential weight and the inclusion of evidence from sensors absent from a sample improved classification performance of Bayesian belief and support for singleton hypotheses. For simple support, inclusion of absent evidence decreased classification rate. The performance of Dempster-Shafer classification using consonant belief functions was comparable to Bayesian and singleton belief. Recommendations are made for further work in biological classification using uncertain reasoning methods, including the combination of multiple-expert opinion, the use of Bayesian networks, and the integration of classification software within a decision support system for water quality assessment.
Resumo:
Hierarchical knowledge structures are frequently used within clinical decision support systems as part of the model for generating intelligent advice. The nodes in the hierarchy inevitably have varying influence on the decisionmaking processes, which needs to be reflected by parameters. If the model has been elicited from human experts, it is not feasible to ask them to estimate the parameters because there will be so many in even moderately-sized structures. This paper describes how the parameters could be obtained from data instead, using only a small number of cases. The original method [1] is applied to a particular web-based clinical decision support system called GRiST, which uses its hierarchical knowledge to quantify the risks associated with mental-health problems. The knowledge was elicited from multidisciplinary mental-health practitioners but the tree has several thousand nodes, all requiring an estimation of their relative influence on the assessment process. The method described in the paper shows how they can be obtained from about 200 cases instead. It greatly reduces the experts’ elicitation tasks and has the potential for being generalised to similar knowledge-engineering domains where relative weightings of node siblings are part of the parameter space.
Resumo:
Speed's theory makes two predictions for the development of analogical reasoning. Firstly, young children should not be able to reason analogically due to an undeveloped PFC neural network. Secondly, category knowledge enables the reinforcement of structural features over surface features, and thus the development of sophisticated, analogical, reasoning. We outline existing studies that support these predictions and highlight some critical remaining issues. Specifically, we argue that the development of inhibition must be directly compared alongside the development of reasoning strategies in order to support Speed's account. © 2010 Psychology Press.
Resumo:
A wide range of essential reasoning tasks rely on contradiction identification, a cornerstone of human rationality, communication and debate founded on the inversion of the logical operators "Every" and "Some." A high-density electroencephalographic (EEG) study was performed in 11 normal young adults. The cerebral network involved in the identification of contradiction included the orbito-frontal and anterior-cingulate cortices and the temporo-polar cortices. The event-related dynamic of this network showed an early negative deflection lasting 500 ms after sentence presentation. This was followed by a positive deflection lasting 1.5 s, which was different for the two logical operators. A lesser degree of network activation (either in neuron number or their level of phase locking or both) occurred while processing statements with "Some," suggesting that this was a relatively simpler scenario with one example to be figured out, instead of the many examples or the absence of a counterexample searched for while processing statements with "Every." A self-generated reward system seemed to resonate the recruited circuitry when the contradictory task is successfully completed.
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This thesis examines the relationship between the European Union (EU) and the Association of Southeast Asian Nations (ASEAN) with a focus on why their normative elements, e.g. values and norms, affect their ties in the post-Cold War era. Since the end of the Cold War, policy-makers and academics have become interested in region-to-region interaction, termed interregionalism. Though interregionalism is considered to have become an indelible feature of post-Cold War international politics, there are question marks over its importance. It is often argued that interregionalism reinforces the collective identity of the regional organisations involved. It is also maintained that its overall relevance to the international system depends on the level of actorness, which is primarily measured in institutional and material terms, of the participant regional organisations. This thesis contends that the normative components of the EU and ASEAN are also fundamental constituents of their actorness and, consequently, define significantly their interregionalism. This is based on a crucial observation that normative factors are of importance to the regional and international relations of the EU and ASEAN. Yet, while they strongly espouse norms and values to guide their internal and external activities, their normative premises radically differ from each other. Furthermore, these normative differences jeopardise their cooperation. Building on this observation the inquiry takes the normative components of the EU and ASEAN as the criterion as well as the focus for investigating their interregionalism. In doing so, it hypothesises that the EU and ASEAN are two different regional actors that adopt two dissimilar sets of norms to conduct their regional and international affairs and that such normative differences hinder their relations. Within this hypothesis, it seeks to address three central questions. First, what are the normative features that constitute the EU and ASEAN as actors in world politics and that make them different from each other? Second, what are the main sources of their normative differences? Finally, why do their normative differences become an obstructive factor in their relationship? To address these issues, the inquiry adopts a constructivist interpretation (of International Relations) and opts for a narrative and empirical inquiry, which is based on information and data acquired from official documents, scholarly works and interviews and questionnaires. In doing so, it finds that as they were born and evolved in two dissimilar temporal and spatial settings, the EU and ASEAN are two different norm entrepreneurs and normative powers. The former advocates a set of liberal cosmopolitan norms whereas the latter champions a set of traditional communitarian principles. Their normative differences become a major obstacle to their cooperation, especially when one regional organisation’s norms are refused or violated by the other. Thus, a key lesson drawn from these findings is that in order to explain more fully EU-ASEAN interregionalism, it is essential to consider their norms, the reasons behind their normative differences and the implication of those differences to their relations
Resumo:
The focus of this paper is young people’s participation in the Occupy protest movement that emerged in the early autumn of 2011. Its concern is with the emotional dimensions of this and in particular the significance of emotions to the reasoning of young people who came to commit significant time and energy to the movement. Its starting point is the critique of emotions as narrowly subjective, whereby the passions that events like Occupy arouse are treated as beyond the scope of human reason. The rightful rejection of this reductionist argument has given rise to an interest in under- standings of the emotional content of social and political protest as normatively con- stituted, but this paper seeks a different perspective by arguing that the emotions of Occupy activists can be regarded as a reasonable force. It does so by discussing find- ings from long-term qualitative research with a Local Occupy movement somewhere in England and Wales. Using the arguments of social realists, the paper explores this data to examine why things matter sufficiently for young people to care about them and how the emotional force that this involves constitutes an indispensable source of reason in young activists’ decisions to become involved in Local Occupy.
Resumo:
Contradiction is a cornerstone of human rationality, essential for everyday life and communication. We investigated electroencephalographic (EEG) and functional magnetic resonance imaging (fMRI) in separate recording sessions during contradictory judgments, using a logical structure based on categorical propositions of the Aristotelian Square of Opposition (ASoO). The use of ASoO propositions, while controlling for potential linguistic or semantic confounds, enabled us to observe the spatial temporal unfolding of this contradictory reasoning. The processing started with the inversion of the logical operators corresponding to right middle frontal gyrus (rMFG-BA11) activation, followed by identification of contradictory statement associated with in the right inferior frontal gyrus (rIFG-BA47) activation. Right medial frontal gyrus (rMeFG, BA10) and anterior cingulate cortex (ACC, BA32) contributed to the later stages of process. We observed a correlation between the delayed latency of rBA11 response and the reaction time delay during inductive vs. deductive reasoning. This supports the notion that rBA11 is crucial for manipulating the logical operators. Slower processing time and stronger brain responses for inductive logic suggested that examples are easier to process than general principles and are more likely to simplify communication. © 2014 Porcaro et al.
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Background: The Melbourne Edge Test (MET) is a portable forced-choice edge detection contrast sensitivity (CS) test. The original externally illuminated paper test has been superseded by a backlit version. The aim of this study was to establish normative values for age and to assess change with visual impairment. Method: The MET was administered to 168 people with normal vision (18-93 years old) and 93 patients with visual impairment (39-97 years old). Distance visual acuity (VA) was measured with a log MAR chart. Results: In those eyes without disease, MET CS was stable until the age of 50 years (23.8 ± .7 dB) after which it decreased at a rate of ≈1.5 dB per decade. Compared with normative values, people with low vision were found to have significantly reduced CS, which could not be totally accounted for by reduced VA. Conclusions: The MET provides a quick and easy measure of CS, which highlights a reduction in visual function that may not be detectable using VA measurements. © 2004 The College of Optometrists.
Resumo:
In recent years, public discourse about German national identity has increasingly focussed on the large foreign population within Germany's borders. Whilst right-wing politicians such as Edmund Stoiber foster fears of identity loss ('Überfremdung'), more liberal observers, and indeed the ruling red-green coalition, acknowledge that multiethnicity has by now become an integral part of this identity. The debate experienced its provisional climax in late 2000 and early 2001. Friedrich Merz, then parliamentary leader of the CDU party, introduced the term 'Leitkultur' into the political discourse. The notion suggests the existence of a clearly identifiable spectrum of German cultural values and proposes that foreigners who wished to live in Germany should adhere to these values. Merz's proposal triggered a wave of highly controversial comments which have been evaluated for the purpose of this paper. It draws on roughly 350 newspaper articles and interviews and aims to introduce the English-speaking reader to the complex range of arguments. The Leitkultur debate is taken as symptomatic of the current state of public discourse about foreigners and national identity in Germany.
Resumo:
The method of case-based reasoning for a solution of problems of real-time diagnostics and forecasting in intelligent decision support systems (IDSS) is considered. Special attention is drawn to case library structure for real-time IDSS (RT IDSS) and algorithm of k-nearest neighbors type. This work was supported by RFBR.