theories of context in logic enable reasoning and deduction in contexts represented as formal objects. Such theories are not readily applicable to systems that learn by induction from a set of examples. Probabilistic ...
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ISBN:
(纸本)354026924X
theories of context in logic enable reasoning and deduction in contexts represented as formal objects. Such theories are not readily applicable to systems that learn by induction from a set of examples. Probabilistic graphical models already provide the tools to exploit context represented as statistical dependences, thereby providing a unified methodology to incorporate context information in learning and inference. Drawing on a case study from optical character recognition, we present the various types of dependences that can occur in pattern classification problems and how such dependences can be exploited to increase classification accuracy. Learning under different conditions require differing amounts and kinds of samples and different trade-offs between modeling error due to overly strict independence assumptions and estimation error of models that are too elaborate for the size of the available training set. With a series of examples based on frames of two patterns we show how each kind of dependence can be represented using graphical models and present examples from other disciplines where the particular dependence frequently occurs.
A model for context-dependent natural language semantics is proposed and formalized in terms of possible worlds. the meaning of a sentence depends on context and at the same time affects that context representing the ...
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ISBN:
(纸本)354026924X
A model for context-dependent natural language semantics is proposed and formalized in terms of possible worlds. the meaning of a sentence depends on context and at the same time affects that context representing the knowledge about the world collected from a discourse. the model fits well with a "flat" semantic representation as first proposed by Hobbs (1985), consisting basically of a conjunction of atomic predications in which all variables are existentially quantified withthe widest possible scope;in our framework, this provides very concise semantic terms as compared with other representations. there is a natural correspondence between the possible worlds semantics and a constraint solver, and it is shown how such a semantics can be defined usingthe programming language of Constraint Handling Rules (Fruhwirth, 1995). Discourse analysis is clearly a process of abduction in this framework, and it is shown that the mentioned constraint solvers serve as effective and efficient abductive engines for the purpose.
作者：
Roque, LicinioCISUC
University of Coimbra - Polo II 3030 Coimbra Portugal
the authors previously proposed the context Engineering (CE) approach to Information Systems Development (ISD) as a framework to organise ideas about previous development experience and to guide future research on spe...
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the authors previously proposed the context Engineering (CE) approach to Information Systems Development (ISD) as a framework to organise ideas about previous development experience and to guide future research on specific ISD methods and techniques. the goals of the CE approach are: to achieve an understanding of the ISD as socio-technical phenomena within a cultural and historical envelope;to provide a framework of problems supported on the relation between context and mediators;and to use contextuality as a key to performing emancipatory movements. Fundamental concepts are the notions of context as figure-ground and as autopoietic flux, of human activity as unit of contextual analysis, of the pervasiveness of mediation in human activity, of socio-technical networks as media and the hypothesis of a heterogeneous social engineering. A framework of development problems is presented along with a discussion of general and process related principles for the CE approach. A fundamental challenge proposed in this approach is the modeling of context as central influencing aspect of development, and the need to find appropriate instruments - concepts, techniques, representations - for modelingcontext as part of the ongoing decision making processes in the flow of ISD development activities. Moreover, we need modeling approaches that enable participation and focus on socio-technical relationships as the fabric of reality.
context effects during Prisoner's Dilemma (PD) game playing are investigated. the Cooperation Index (CI) - a quantity computed as a relation between payoffs - defines a cooperativeness scale, along which PD games ...
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ISBN:
(纸本)354026924X
context effects during Prisoner's Dilemma (PD) game playing are investigated. the Cooperation Index (CI) - a quantity computed as a relation between payoffs - defines a cooperativeness scale, along which PD games can be distributed. context is selected by manipulating the Cl range of the games played. It is found that the level of cooperation depends not only on the CI of the current game but also on the Cl of the other games in the sequence. the influence of context on the full Cl scale is investigated by introducing probe games covering the whole Cl range. the results are compared withthe prediction of a model that takes into account the current game, the previous play history, and the predicted opponent's move. the model is found to be sensitive to boththe Cl and to the CI of the other games form the game set and a very good agreement between the model and the experimental data was found.
After more than three decades of research, the Decision Support Systems (DSS) community is still looking for a unified and standardized DSS development methodology. In this paper, we argue that the existing solutions ...
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After more than three decades of research, the Decision Support Systems (DSS) community is still looking for a unified and standardized DSS development methodology. In this paper, we argue that the existing solutions remain too distinct and project-specific because they fail to properly consider the context of the target DSS in their processes. this paper describes a new approach, whose goal is to formalize the notion of context in the study of DSS development. the proposed approach is based on the concept of value-based software engineering. It is structured around two techniques called the benefits-realization approach and the realization feedback process. An example is provided to illustrate how an impractical, context-free DSS development life cycle can be turned into a context-based life cycle focusing on the most success-critical aspects of the target DSS.
In order to help address problems of information overload in digital imagery task domains, we have developed an interactive approach to the capture and reuse of image context information. Our framework models differen...
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ISBN:
(纸本)354026924X
In order to help address problems of information overload in digital imagery task domains, we have developed an interactive approach to the capture and reuse of image context information. Our framework models different aspects of the relationship between images and the domain tasks that they support by monitoring the interactive manipulation and annotation of task-relevant imagery. In particular, a strong focus on task context serves to ground image annotations in domain specific goals. this contrasts with prevalent annotation schemes that focus on what individual images contain but that provide no context for which, if any, of those aspects are important to users. Our work attempts to leverage a measure of the user's intentions with regard to tasks that they address. We analyze human-computer interaction information that enables us to infer why image contents are important in a particular context and how specific images have been used to address particular domain goals.
the paper presents an approach to decision making in the dynamic environment. the approach is aimed at modeling and solving the decision maker's problem. the problem is modeled by abstract and operational contexts...
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Within one model, behavioural consistency of its constituents is often problematic. Within UML such horizontal behavioural consistency between the objects of a concrete model, is particularly needed in the context of ...
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ISBN:
(纸本)354025630X
Within one model, behavioural consistency of its constituents is often problematic. Within UML such horizontal behavioural consistency between the objects of a concrete model, is particularly needed in the context of dynamic patterns. Here, we investigate delegation, which is fundamental to patterns that separate the locality of receiving a request, and one or more localities actually handling it. We specify delegation by means of the coordination language Paradigm. In particular, we present some variants of delegation in the context of a broker pattern and clarify how the Paradigm notions are the basis for understanding a solution as well as for adapting it to deal with other dynamic features.
Appraising the environmental context in which an organization deploys its activity is a necessity in order to make appropriate decisions and adapting strategies to a context in constant evolution, especially in a time...
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Appraising the environmental context in which an organization deploys its activity is a necessity in order to make appropriate decisions and adapting strategies to a context in constant evolution, especially in a time where this context is increasingly complex, uncertain and disruptive. Decision makers therefore need more than ever better tools that aid them to analyze their environment, providing them the most pertinent information to take the most appropriate decisions. In this paper, we attempt to propose a set of reusable artifacts that would facilitate the development of decision support systems for assessing the organization's environment. In particular, we propose an ontology that defines the different elements that shall be taken into account in order to effectively and efficiently scan an environment. We then provide an overview of some analysis techniques and tools that could be useful to analyze, assess and visualize essential information about these elements. Finally, we present two decision support system prototypes that allow a partial analysis of the environment using appropriate interaction and visualization techniques.
A stock market decision making makes a compelling case for the use of context aware systems that can adapt to a context behavior known as 'random walk'. To defend such a proposition the paper adopts the formul...
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A stock market decision making makes a compelling case for the use of context aware systems that can adapt to a context behavior known as 'random walk'. To defend such a proposition the paper adopts the formulation typically used in sensor driven applications that involves critical context characteristics of pervasiveness and instability. From the pervasive perspective the paper concentrates on the ability to characterize a context-state trajectory behavior in real-time to proactively estimate the trend of context change. From the perspective of instability it discusses context related mechanisms such as hedging with derivative instruments as a way to caliber context aware system sensitivity to contextual changes. To validate the idea the paper introduces a special case of an equity option portfolio that is simultaneously delta, gamma and Vega neutral, to deal with extreme context-state exhibiting unpredictable time-varying behavior. Based on some preliminary results of real life experimentation the paper concludes with a continuing current debate on the distinctive merits of reactive versus proactive context.
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