Browsing by Subject "Knowledge representation"
Now showing 1 - 10 of 10
Results Per Page
Sort Options
Item Open Access Formalization of the traffic world in the C action language(Bilkent University, 2000) Erdoğan, Selim T.Reasoning about actions and effects of actions is an important task in Artifical Intelligence, with connections to knowledge representation and planning. Many formal methods for representing actions and inferring their effects have been developed over the years (e.g. action languages, fluent calculus, situation calculus). Howewer, the examples formalized so far have been "toy" domains of very small sizes. Successful formalizations of scenarios of nontrivial size are needed in order to show that these methods are suitable for real applications and to assess the strong and weak sides of different methods. The C action language is a logic programming language designed to represent the effects of actions on fluents. In this thesis we formalize the TRAFFIC scenario world - a domain of moderate size, specified at the Logic Modelling Workshop at http://www.ida.liu.se/ext/etai/lmw/ - using the C action language. Example planning problems using the formalization are successfully solved using the Causal Calculator - available at http://www.cs.utexas.edu/users/tag/cc/ -, a program for planning and querying in action domains. The formalization is contrasted with previous work on the TRAFFIC world, namely the formalization of A. Henschel and M. Thielscher using the fluent calculus.Item Open Access A fundamental and theoretical framework for an intelligent CAD system(Pergamon Press, 1990) Akman, V.; Hagen, P. J. W. T.; Tomiyama, T.Currently, there exists a line of research in mechanical CAD that is directed towards using AI and knowledge engineering ideas, but truly unifying approaches in this respect are lacking. The authors hope to fill this gap via a logic-based, theoretical approach. A formulation is given for how a designer's apprentice (or a design workbench) can be established. The relevance of naive physics and commonsense reasoning in machine design are demonstrated. As for the software development methodology several aspects of software engineering are considered. A design base language which is built upon logic programming and object-oriented programming paradigm is proposed. © 1990.Item Open Access Graph aware caching policy for distributed graph stores(IEEE, 2015-03) Aksu, Hidayet; Canım, M.; Chang, Y.-C.; Körpeoğlu, İbrahim; Ulusoy, ÖzgürGraph stores are becoming increasingly popular among NOSQL applications seeking flexibility and heterogeneity in managing linked data. Conceptually and in practice, applications ranging from social networks, knowledge representations to Internet of things benefit from graph data stores built on a combination of relational and non-relational technologies aimed at desired performance characteristics. The most common data access pattern in querying graph stores is to traverse from a node to its neighboring nodes. This paper studies the impact of such traversal pattern to common data caching policies in a partitioned data environment where a big graph is distributed across servers in a cluster. We propose and evaluate a new graph aware caching policy designed to keep and evict nodes, edges and their metadata optimized for query traversal pattern. The algorithm distinguishes the topology of the graph as well as the latency of access to the graph nodes and neighbors. We implemented graph aware caching on a distributed data store Apache HBase in the Hadoop family. Performance evaluations showed up to 15x speedup on the benchmark datasets preferring our new graph aware policy over non-aware policies. We also show how to improve the performance of existing caching algorithms for distributed graphs by exploiting the topology information. © 2015 IEEE.Item Open Access Information-based approach to punctuation(AAAI, 1997-07) Say, BilgeThis thesis analyzes, in an information-based framework, the semantic and discourse aspects of punctuation, drawing computational implications for Natural Language Processing (NLP) systems. The Discourse Representation Theory (DRT) is taken as the theoretical framework of the thesis. By following this analysis, it is hoped that NLP software writers will be able to make use of the punctuation marks effectively as well as reveal interesting linguistic phenomena in conjunction with punctuation marks.Item Open Access Issues in commonsense set theory(Springer/Kluwer Academic Publishers, 1994) Pakkan, M.; Akman, V.The success of set theory as a foundation for mathematics inspires its use in artificial intelligence, particularly in commonsense reasoning. In this survey, we briefly review classical set theory from an AI perspective, and then consider alternative set theories. Desirable properties of a possible commonsense set theory are investigated, treating different aspects like cumulative hierarchy, self-reference, cardinality, etc. Assorted examples from the ground-breaking research on the subject are also given. © 1995 Kluwer Academic Publishers.Item Open Access An ontology-based universal design knowledge support system(Elsevier, 2011-05) Afacan, Yasemin; Demirkan, H.An effective and efficient knowledge support system is crucial for universal design process, as it has become a major design issue in the last decade with the growth of the elderly population and disabled people. There are a limited number of CAD investigations on the nature of knowledge processing that supports the cognitive activities of universal design process. Therefore, this paper proposes an ontology-based computer-assisted universal design (CAUD) plug-in tool that supports designers in developing satisfactory universal design solutions in the conceptual design phase. The required knowledge processing and representation of the developed tool is motivated by the ontological language. It is based on the multiple divergence-convergence cognitive strategies and cognitive needs of designers in the analysis/synthesis/evaluation operations. The CAUD plug-in tool is the first attempt to interface the universal design knowledge ontologically and respond to the requirements of conceptual design phase. According to the user acceptance study, the tool is assessed as useful, understandable, efficient, supportive and satisfactory.Item Open Access Stability and plasticity : constructing cognitive agents(Bilkent University, 2006) Bozyiğit, ÖgeThe AI field is currently dominated by domain-specific approaches to intelligence and cognition instead of being driven by the aim of modeling general human intelligence and cognition. This is despite the fact that the work widely regarded as marking the birth of AI was the project of creating a general cognitive architecture by Newell and Simon 1959. This thesis aims to examine recently designed models and their various cognitive features and limitations in preparation for building our own comprehensive model that would aim to address their limitations and give a better account for human cognition. The models differ in the kind of cognitive capabilities they view as the most important. They also differ in whether their foundation is built on symbolic or sub-symbolic atomic structures. Furthermore, we will look at studies in the philosophy and cognitive psychology domain in order to better understand the requirements that need to be met in order for a system to emulate general human cognition.Item Open Access Supervised machine learning algorithm for arrhythmia analysis(IEEE, 1997) Güvenir, H. Altay; Acar, Burak; Demiröz, Gülşen; Çekin, A.A new machine learning algorithm for the diagnosis of cardiac arrhythmia from standard 12 lead ECG recordings is presented. The algorithm is called VFI5 for Voting Feature Intervals. VFI5 is a supervised and inductive learning algorithm for inducing classification knowledge from examples. The input to VFI5 is a training set of records. Each record contains clinical measurements, from ECG signals and some other information such as sex, age, and weight, along with the decision of an expert cardiologist. The knowledge representation is based on a recent technique called Feature Intervals, where a concept is represented by the projections of the training cases on each feature separately. Classification in VFI5 is based on a majority voting among the class predictions made by each feature separately. The comparison of the VFI5 algorithm indicates that it outperforms other standard algorithms such as Naive Bayesian and Nearest Neighbor classifiers.Item Open Access The systems biology graphical notation(Nature Publishing Group, 2009-08) Le Novère, N.; Hucka, M.; Mi, H.; Moodie, S.; Schreiber, F.; Sorokin, A.; Demir, Emek; Wegner, K.; Aladjem, M. I.; Wimalaratne, S. M.; Bergman, F. T.; Gauges, R.; Ghazal, P.; Kawaji, H.; Li, L.; Matsuoka, Y.; Villéger, A.; Boyd, S. E.; Calzone, L.; Courtot, M.; Doğrusöz, Uğur; Freeman, T. C.; Funahashi, A.; Ghosh, S.; Jouraku, A.; Kim, S.; Kolpakov, F.; Luna, A.; Sahle, S.; Schmidt, E.; Watterson, S.; Wu, G.; Goryanin, I.; Kell, D. B.; Sander, C.; Sauro, H.; Snoep, J. L.; Kohn, K.; Kitano, H.Circuit diagrams and Unified Modeling Language diagrams are just two examples of standard visual languages that help accelerate work by promoting regularity, removing ambiguity and enabling software tool support for communication of complex information. Ironically, despite having one of the highest ratios of graphical to textual information, biology still lacks standard graphical notations. The recent deluge of biological knowledge makes addressing this deficit a pressing concern. Toward this goal, we present the Systems Biology Graphical Notation (SBGN), a visual language developed by a community of biochemists, modelers and computer scientists. SBGN consists of three complementary languages: process diagram, entity relationship diagram and activity flow diagram. Together they enable scientists to represent networks of biochemical interactions in a standard, unambiguous way. We believe that SBGN will foster efficient and accurate representation, visualization, storage, exchange and reuse of information on all kinds of biological knowledge, from gene regulation, to metabolism, to cellular signaling. © 2009 Nature America, Inc.Item Open Access V. Lifschitz, ed., formalizing common sense: papers by John McCarthy(Elsevier BV, 1995) Akman, V.A review is presented of Lifschitz's collection of seventeen papers written by McCarthy on the subject of common sense. The book opens with a fine overview of McCarthy's research in artificial intelligence (AI). Lifschitz offers an admirably succinct account of the development of McCarthy's ideas on common sense from the early days of AI to his current work. Lifschitz's introduction is especially useful in appreciating the dramatically original and permanently influential nature of McCarthy's work. While McCarthy's papers collected in this volume were written over the span of almost three decades, Lifschitz correctly observes that the underlying concern has always been the same: to understand and model the intellectual ability realized by human common sense.