The Experts below are selected from a list of 21759135 Experts worldwide ranked by ideXlab platform
Bart Selman - One of the best experts on this subject based on the ideXlab platform.
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the comparative linguistics of knowledge representation
International Joint Conference on Artificial Intelligence, 1995Co-Authors: Goran Gogic, Christos H. Papadimitriou, Henry Kautz, Bart SelmanAbstract:We develop a methodology for comparing knowledge representation formalisms in terms of their "representational succinctness," that is, their ability to express knowledge situations relatively efficiently. We use this framework for comparing many important formalisms for knowledge base representation: propositional logic, default logic, circumscription, and model preference defaults; and, at a lower level, Horn formulas, characteristic models, decision trees, disjunctive normal form, and conjunctive normal form. We also show that adding new variables improves the effective expressibility of certain knowledge representation formalisms.
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IJCAI (1) - The comparative linguistics of knowledge representation
1995Co-Authors: Goran Gogic, Christos H. Papadimitriou, Henry Kautz, Bart SelmanAbstract:We develop a methodology for comparing knowledge representation formalisms in terms of their "representational succinctness," that is, their ability to express knowledge situations relatively efficiently. We use this framework for comparing many important formalisms for knowledge base representation: propositional logic, default logic, circumscription, and model preference defaults; and, at a lower level, Horn formulas, characteristic models, decision trees, disjunctive normal form, and conjunctive normal form. We also show that adding new variables improves the effective expressibility of certain knowledge representation formalisms.
Goran Gogic - One of the best experts on this subject based on the ideXlab platform.
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the comparative linguistics of knowledge representation
International Joint Conference on Artificial Intelligence, 1995Co-Authors: Goran Gogic, Christos H. Papadimitriou, Henry Kautz, Bart SelmanAbstract:We develop a methodology for comparing knowledge representation formalisms in terms of their "representational succinctness," that is, their ability to express knowledge situations relatively efficiently. We use this framework for comparing many important formalisms for knowledge base representation: propositional logic, default logic, circumscription, and model preference defaults; and, at a lower level, Horn formulas, characteristic models, decision trees, disjunctive normal form, and conjunctive normal form. We also show that adding new variables improves the effective expressibility of certain knowledge representation formalisms.
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IJCAI (1) - The comparative linguistics of knowledge representation
1995Co-Authors: Goran Gogic, Christos H. Papadimitriou, Henry Kautz, Bart SelmanAbstract:We develop a methodology for comparing knowledge representation formalisms in terms of their "representational succinctness," that is, their ability to express knowledge situations relatively efficiently. We use this framework for comparing many important formalisms for knowledge base representation: propositional logic, default logic, circumscription, and model preference defaults; and, at a lower level, Horn formulas, characteristic models, decision trees, disjunctive normal form, and conjunctive normal form. We also show that adding new variables improves the effective expressibility of certain knowledge representation formalisms.
Hui Guo - One of the best experts on this subject based on the ideXlab platform.
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a class of discrete transformation survival models with application to default probability prediction
Journal of the American Statistical Association, 2012Co-Authors: Adam A Ding, Shaonan Tian, Hui GuoAbstract:Corporate bankruptcy prediction plays a central role in academic finance research, business practice, and government regulation. Consequently, accurate default probability prediction is extremely important. We propose to apply a discrete transformation family of survival models to corporate default risk predictions. A class of Box-Cox transformations and logarithmic transformations is naturally adopted. The proposed transformation model family is shown to include the popular Shumway model and the grouped relative risk model. We show that a transformation parameter different from those two models is needed for default prediction using a bankruptcy dataset. In addition, we show using out-of-sample validation statistics that our model improves performance. We use the estimated default probability to examine a popular asset pricing question and determine whether default risk has carried a premium. Due to some distinct features of the bankruptcy application, the proposed class of discrete transformation surviv...
Josevictor Riosrull - One of the best experts on this subject based on the ideXlab platform.
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a quantitative theory of unsecured consumer credit with risk of default
Econometrica, 2007Co-Authors: Satyajit Chatterjee, Dean P Corbae, Makoto Nakajima, Josevictor RiosrullAbstract:The authors study, theoretically and quantitatively, the general equilibrium of an economy in which households smooth consumption by means of both a riskless asset and unsecured loans with the option to default. The default option resembles a bankruptcy filing under Chapter 7 of the U.S. Bankruptcy Code. Competitive financial intermediaries offer a menu of loan sizes and interest rates wherein each loan makes zero profits. They prove the existence of a steady-state equilibrium and characterize the circumstances under which a household defaults on its loans. They show that their model accounts for the main statistics regarding bankruptcy and unsecured credit while matching key macroeconomic aggregates and the earnings and wealth distributions. They use this model to address the implications of a recent policy change that introduces a form of “means-testing” for households contemplating a Chapter 7 bankruptcy filing. They find that this policy change yields large welfare gains. ; Also issued as Payment Cards Center Discussion Paper No. 07-08, 05-12, and 01-01 ; Supersedes Working Paper No. 05-18 and 02-6
Huyen Pham - One of the best experts on this subject based on the ideXlab platform.
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optimal investment with counterparty risk a default density model approach
Finance and Stochastics, 2011Co-Authors: Ying Jiao, Huyen PhamAbstract:We consider a financial market with a stock exposed to a counterparty risk inducing a jump in the price, and which can still be traded after this default time. The jump represents a loss or gain of the asset value at the default of the counterparty. We use a default-density modelling approach, and address in this incomplete market context the problem of expected utility maximization from terminal wealth. We show how this problem can be suitably decomposed in two optimization problems in a default-free framework: an after-default utility maximization and a global before-default optimization problem involving the former one. These two optimization problems are solved explicitly, respectively, by duality and dynamic programming approaches, and provide a detailed description of the optimal strategy. We give some numerical results illustrating the impact of counterparty risk and the loss or gain given default on optimal trading strategies, in particular with respect to the Merton portfolio selection problem. For example, this explains how an investor can take advantage of a large loss of the asset value at default in extreme situations as observed during the financial crisis.
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Optimal investment with counterparty risk: a default-density modeling approach
2009Co-Authors: Ying Jiao, Huyen PhamAbstract:We consider a financial market with a stock exposed to a counterparty risk indu\-cing a drop in the price, and which can still be traded after this default time. We use a default-density modeling approach, and address in this incomplete market context the expected utility maximization from terminal wealth. We show how this problem can be suitably decomposed in two optimization problems in complete market framework: an after-default utility maximization and a global before-default optimization problem involving the former one. These two optimization problems are solved explicitly, respectively by duality and dynamic programming approaches, and provide a fine understanding of the optimal strategy. We give some numerical results illustrating the impact of counterparty risk and the loss given default on optimal trading strategies, in particular with respect to the Merton portfolio selection problem.
