首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
The human brain cortex is very complex structure containing folds (gyri) and fissures (sulci) that were the subject of our study in this paper. The sulcus is one of the most important features in order to know the different functions areas of the brain. The exact identification of sulci on human brain using MRI images is helpful in many studies and applications related to brain diseases and human behavior. Automatic labeling of cortical sulci with all this complexity and inter-subject variability, this is considered non-trivial task. In this paper, we have proposed a new graph based approach of automatic labeling of cortical sulci with parallel and distributed algorithms using graph matching and generalized median graph. The graph matching is very important in many studies and applications such as pattern recognition and classification. The generalized median graph of a set of graphs is a way to represent a set of graphs by a comprehensive graph that minimizes the sum of the distances to all graphs. We have used the characteristics of shape, orientation and location to describe the sulci. The results that we have obtained prove that our approach is accurate and acceptable in this field which uses the graph matching for automatic labeling of cortical sulci.  相似文献   

2.
Adam Přenosil 《Studia Logica》2016,104(3):389-415
We introduce a novel expansion of the four-valued Belnap–Dunn logic by a unary operator representing reductio ad contradictionem and study its algebraic semantics. This expansion thus contains both the direct, non-inferential negation of the Belnap–Dunn logic and an inferential negation akin to the negation of Johansson’s minimal logic. We formulate a sequent calculus for this logic and introduce the variety of reductio algebras as an algebraic semantics for this calculus. We then investigate some basic algebraic properties of this variety, in particular we show that it is locally finite and has EDPC. We identify the subdirectly irreducible algebras in this variety and describe the lattice of varieties of reductio algebras. In particular, we prove that this lattice contains an interval isomorphic to the lattice of classes of finite non-empty graphs with loops closed under surjective graph homomorphisms.  相似文献   

3.
A set of data has a Guttman scale if and only if a corresponding graph is a threshold graph. In this paper we relate the concepts of disjunctive and conjuctive Guttman scales, and biorder dimension to the threshold dimension of a graph. For those graphical properties that can be tested in polynomial time, the comparable Guttman scaling techniques can be performed in polynomial time. Fast algorithms are provided for computing a Guttman scale, and the conjunctive and disjunctive dimension of data with no 3-crowns. We define an extended Guttman scale to indicate strength of agreement, dominance, etc., and show that this, too, exists if and only if a particular graph is a threshold graph.  相似文献   

4.
Paraconsistent logic from a modal viewpoint   总被引:1,自引:0,他引:1  
In this paper we study paraconsistent negation as a modal operator, considering the fact that the classical negation of necessity has a paraconsistent behavior. We examine this operator on the one hand in the modal logic S5 and on the other hand in some new four-valued modal logics.  相似文献   

5.
CORTEX is a cognitive robotics architecture inspired by three key ideas: modularity, internal modelling and graph representations. CORTEX is also a computational framework designed to support early forms of intelligence in real world, human interacting robots, by selecting an a priori functional decomposition of the capabilities of the robot. This set of abilities was then translated to computational modules or agents, each one built as a network of software interconnected components. The nature of these agents can range from pure reactive modules connected to sensors and/or actuators, to pure deliberative ones, but they can only communicate with each other through a graph structure called Deep State Representation (DSR). DSR is a short-term dynamic representation of the space surrounding the robot, the objects and the humans in it, and the robot itself. All these entities are perceived and transformed into different levels of abstraction, ranging from geometric data to high-level symbolic relations such as “the person is talking and gazing at me”. The combination of symbolic and geometric information endows the architecture with the potential to simulate and anticipate the outcome of the actions executed by the robot. In this paper we present recent advances in the CORTEX architecture and several real-world human-robot interaction scenarios in which they have been tested. We describe our interpretation of the ideas inspiring the architecture and the reasons why this specific computational framework is a promising architecture for the social robots of tomorrow.  相似文献   

6.
本文考察了评价算子,即刻画认知主体如何借助评价依据来理性评价新信息的算子,它放弃新信息中部分不可信信息,但是与传统收缩算子不同,它不指定收缩的信息而只要求评价结果与评价依据相一致。S.O.Hansson认为以单个句子作为新信息的非优先信念修正具有三种模式:决策–修正(Decision-Revision)、整合选择(Integrated Choice)和膨胀–巩固(Expansion-Consolidation)。评价算子单独刻画了非优先复合修正决策–修正模式的决策模块,对于修正模块这里不作探讨。我们先按AGM信念修正模式对评价算子进行了公理性刻画,接着通过不一致核心集和一致保留集分别构造了核心评价算子和部分交评价算子,然后分别证明了这两种算子与公理性刻画之间的表达定理,最后对评价算子和其他相关工作进行了比较。  相似文献   

7.
In this paper we propose an extension of Defeasible Logic to represent and compute different concepts of defeasible permission. In particular, we discuss some types of explicit permissive norms that work as exceptions to opposite obligations or encode permissive rights. Moreover, we show how strong permissions can be represented both with, and without introducing a new consequence relation for inferring conclusions from explicit permissive norms. Finally, we illustrate how a preference operator applicable to contrary-to-duty obligations can be combined with a new operator representing ordered sequences of strong permissions. The logical system is studied from a computational standpoint and is shown to have linear computational complexity.  相似文献   

8.
Abolitionism is the view that if no one is responsible, then we ought to abandon the reactive attitudes (e.g. resentment, contempt, and guilt). Proponents suggest that reactive attitudes can be replaced in our emotional repertoire by non-reactive analogues (e.g. sadness and disappointment). In this paper, I dispute and reject a common challenge to abolitionism according to which the reactive attitudes are necessary for protesting unfairness and maintaining social harmony. While other abolitionists dispute the empirical basis of this objection, I focus on its implications. I argue that even if non-reactive analogues cannot perform the interpersonal and social functions of reactive attitudes, it does not follow that the losses of abandoning them outweigh the gains of retaining them. The force of the challenge rests on a mistake, identified by John Stuart Mill among others, that is common when evaluating entrenched social practices.  相似文献   

9.
Ni, Crain, and Shankweiler (1996) present evidence to suggest that the focus operator only can guide how reduced relative clause sentences are initially parsed. In this paper, we demonstrate that this does not hold for relative clause sentences that start with a noun-phrase, verb, noun-phrase construction. We report an eye movement study in which subjects read reduced and unreduced sentences of this type with and without the focus operator only. There were longer first-pass reading times in the critical region of reduced sentences than in the same region of unreduced sentences, regardless of the inclusion of only. Furthermore, readers spent less time re-inspecting portions of text after being garden pathed when reading reduced relative clause sentences that contained the focus operator than when reading reduced relative clause sentences that did not. We conclude that subjects initially syntactically misanalysed reduced relative clause sentences with and without only, and the inclusion of a focus operator facilitated recovery procedures rather than guiding initial parsing. These results are inconsistent with the referential theory and undermine the conclusions of Ni et al. (1996).  相似文献   

10.
Alessandro Giordani 《Synthese》2014,191(8):1909-1923
The concept of knowledge can be modelled in epistemic modal logic and, if modelled by using a standard modal operator, it is subject to the problem of logical omniscience. The classical solution to this problem is to distinguish between implicit and explicit knowledge and to construe the knowledge operator as capturing the concept of implicit knowledge. In addition, since a proposition is said to be implicitly known just in case it is derivable from the set of propositions that are explicitly known by using a certain set of logical rules, the concept of implicit knowledge is definable on the basis of the concept of explicit knowledge. In any case, both implicit and explicit knowledge are typically characterized as factive, i.e. such that it is always the case that what is known is also true. The aim of the present paper is twofold: first, we will develop a dynamic system of explicit intersubjective knowledge that allows us to introduce the operator of implicit knowledge by definition; secondly, we will show that it is not possible to hold together the following two theses: (1) the concept of implicit knowledge is definable along the lines indicated above and (2) the concept of implicit knowledge is factive.  相似文献   

11.
Herrmann  Burghard 《Studia Logica》1997,58(2):305-323
In [14] we used the term finitely algebraizable for algebraizable logics in the sense of Blok and Pigozzi [2] and we introduced possibly infinitely algebraizable, for short, p.i.-algebraizable logics. In the present paper, we characterize the hierarchy of protoalgebraic, equivalential, finitely equivalential, p.i.-algebraizable, and finitely algebraizable logics by properties of the Leibniz operator. A Beth-style definability result yields that finitely equivalential and finitely algebraizable as well as equivalential and p.i.-algebraizable logics can be distinguished by injectivity of the Leibniz operator. Thus, from a characterization of equivalential logics we obtain a new short proof of the main result of [2] that a finitary logic is finitely algebraizable iff the Leibniz operator is injective and preserves unions of directed systems. It is generalized to nonfinitary logics. We characterize equivalential and, by adding injectivity, p.i.-algebraizable logics.  相似文献   

12.
Local Change     
An agent can usually hold a very large number of beliefs. However, only a small part of these beliefs is used at a time. Efficient operations for belief change should affect the beliefs of the agent locally, that is, the changes should be performed only in the relevant part of the belief state. In this paper we define a local consequence operator that only considers the relevant part of a belief base. This operator is used to define local versions of the operations for belief change. Representation theorems are given for the local operators.  相似文献   

13.
This study manipulated the graphical representation of options by framing the physical characters in figures and found that preferences could be affected even when the words and numbers of the problem were constant. Based on attribute substitution theory and an equate‐to‐differentiate approach, we proposed a two‐process model of graph‐framing effects. In the first mental process, the graph‐editing process, the physical features (e.g., distance, size) represented in the graph are visually edited, and the perceived numerical difference between the options is judged based on its physical features. The second mental process, the preferential choice process, occurs by an equate‐to‐differentiate approach in which people seek to equate the difference between options on the dimension on which the difference is smaller, thus leaving the greater other‐dimensional difference to be the determinant of the final choice. Four experiments were tested for graph‐framing effects. Experiment 1 found a graph‐framing effect in coordinate graphs resting on the (de)compression of the scales employed in the figures. Experiment 2 revealed additional graph‐framing effects in other question scenarios and showed that preference changes were mediated by perceived numerical distances. Experiment 3 further confirmed the presence of graph‐framing effects in sector graphs similar to those found in coordinate ones. Experiment 4 suggested that such graph‐framing effects could be eliminated when logical processing (e.g., introducing a mathematical operation before a choice task) was encouraged. This paper discusses related research and a possible substrate basis for graph‐framing effects. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

14.
A discussion of the scope that exists for the normative assessment of blame. The paper starts from the assumption that blame is to be understood in terms of the reactive attitudes. A particular crux is the question of whether blame can be assessed critically if conditions are in place that render the reactive attitudes apt or warranted. The paper argues that even warranted blame can be managed critically and that this is something we often have reason to do, given the oppositional nature of reactive blame. The point is illustrated through a discussion of forgiveness and hypocrisy. A further claim is that, once reasons for reactive blame are distinguished from distinct reasons for managing it in different ways, space opens up for interesting global challenges to reactive blame, even when it is internally apt or warranted.  相似文献   

15.
A key problem in robotics is the construction of a map from its environment. This map could be used in different tasks, like localization, recognition, obstacle avoidance, etc. Besides, the simultaneous location and mapping (SLAM) problem has had a lot of interest in the robotics community. This paper presents a new method for visual mapping, using topological instead of metric information. For that purpose, we propose prior image segmentation into regions in order to group the extracted invariant features in a graph so that each graph defines a single region of the image. Although others methods have been proposed for visual SLAM, our method is complete, in the sense that it makes all the process: it presents a new method for image matching; it defines a way to build the topological map; and it also defines a matching criterion for loop-closing. The matching process will take into account visual features and their structure using the graph transformation matching (GTM) algorithm, which allows us to process the matching and to remove out the outliers. Then, using this image comparison method, we propose an algorithm for constructing topological maps. During the experimentation phase, we will test the robustness of the method and its ability constructing topological maps. We have also introduced new hysteresis behavior in order to solve some problems found building the graph.  相似文献   

16.
In this paper we address the problem of combining a logic with nonmonotonic modal logic. In particular we study the intuitionistic case. We start from a formal analysis of the notion of intuitionistic consistency via the sequent calculus. The epistemic operator M is interpreted as the consistency operator of intuitionistic logic by introducing intuitionistic stable sets. On the basis of a bimodal structure we also provide a semantics for intuitionistic stable sets.  相似文献   

17.
In this paper we present a sequent calculus for propositional dynamic logic built using an enriched version of the tree-hypersequent method and including an infinitary rule for the iteration operator. We prove that this sequent calculus is theoremwise equivalent to the corresponding Hilbert-style system, and that it is contraction-free and cut-free. All results are proved in a purely syntactic way.  相似文献   

18.
Abolitionism is the view that if no one is responsible, we ought to abandon the reactive attitudes. This paper defends abolitionism against the claim, made by P.F. Strawson and others, that abandoning these attitudes precludes the formation and maintenance of valuable personal relationships. These anti-abolitionists claim (a) that one who abandons the reactive attitudes is unable to take personally others’ attitudes and actions regarding her, and (b) that taking personally is necessary for certain valuable relationships. I dispute both claims and argue that this objection exaggerates the role of the reactive attitudes and underestimates the importance of non-reactive moral emotions.  相似文献   

19.
本文基于经典一阶逻辑句法的逻辑优先性分析,把Hintikka的独立联结词和独立量词扩展到多值逻辑中。我们给出IF多值逻辑的句法,并使用不完全信息的语义赋值博弈解释了IF多值逻辑。  相似文献   

20.
If I do you a good turn, you may respond with gratitude and express that gratitude by saying “Thank you.” Similarly, if I insult you, you may react with resentment which you express by shouting, “Screw you!” or something of the sort. Broadly put, when confronted with another’s morally significant conduct, we are inclined to respond with a reactive attitude and to express that reactive attitude in speech. A number of familiar speech acts have a call-and-response structure. Questions, demands and hails are all call-types, and each seeks a defining response. Questions seek answers, demands seek compliance, and a hail, for example, “Hi Coleen” seeks a “Hi” in return. Many theorists claim that expressions of the reactive attitudes also have this structure. Yet, this insight raises a number of questions. There are, after all, many familiar call-types, not only questions, demands and hails, but also requests, invitations, recommendations and entreaties. Given this, it is natural to wonder whether the expressed reactive attitudes are a sui generis call-type or whether they can be properly assimilated to one of the better-known forms. Further, we might wonder about the response component. It is utterly familiar that the response suited to a demand is compliance, and that the response sought by a question is an answer, but what response do the expressed reactive attitudes seek? The answer to this question is not similarly ready to hand. In this paper, I provide a recognition-based theory of the call-and-response structure of the expressed reactive attitudes. On my account, both the positive and negative expressed reactive attitudes are modes of recognition that seek for their target to give expression to her recognition of having been appropriately recognized. In the negative case, the target does this by feeling and expressing guilt or remorse, and in the positive case, by feeling and expressing self-approbation.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号