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Grounded Semantic Composition for Visual Scenes

Journal of Artificial Intelligence Research

We present a visually-grounded language understanding model based on a study of how people verbally describe objects in scenes. The emphasis of the model is on the combination of individual word meanings to produce meanings for complex referring expressions. The model has been implemented, and it is able to understand a broad range of spatial referring expressions. We describe our implementation of word level visually-grounded semantics and their embedding in a compositional parsing framework. The implemented system selects the correct referents in response to natural language expressions for a large percentage of test cases. In an analysis of the system's successes and failures we reveal how visual context influences the semantics of utterances and propose future extensions to the model that take such context into account.


Applying Inductive Logic Programming to Predicting Gene Function

AI Magazine

One of the fastest advancing areas of modern science is functional genomics. This science seeks to understand how the complete complement of molecular components of living organisms (nucleic acid, protein, small molecules, and so on) interact together to form living organisms. Functional genomics is of interest to AI because the relationship between machines and living organisms is central to AI and because the field is an instructive and fun domain to apply and sharpen AI tools and ideas, requiring complex knowledge representation, reasoning, learning, and so on. This article describes two machine learning (inductive logic programming [ILP])-based approaches to the bioinformatic problem of predicting protein function from amino acid sequence. The first approach is based on using ILP as a way of bootstrapping from conventional sequence-based homology methods. The second approach used protein-functional ontologies to provide function classes and a hybrid ILP method to predict function directly from sequence. Both ILP approaches were successful in producing accurate prediction rules that could biologically be interpreted. The work was also of interest to machine learning research because it highlighted the flexibility of ILP systems in dealing with heterogeneous data, the importance of problems where classes are related hierarchically, and problems where examples have more than one functional class.


Applications of Case-Based Reasoning in Molecular Biology

AI Magazine

Thus, one of the primary goals of a CBR system is to find the most similar, or most relevant, cases for new input problems. The effectiveness of CBR depends on the quality and quantity of cases in a case base. In some domains, even a small number of cases provide good solutions, but in other domains, an increased number of unique cases improves problemsolving capabilities of CBR systems because there are more experiences to draw on. The reader can find detailed complete theories, and rapid evolution; reasoning descriptions of the CBR process and systems in is often based on experience rather Kolodner (1993). Experts remember are presented in Leake (1996), and practically positive experiences for possible reuse of solutions; negative experiences are used to avoid oriented descriptions of CBR can be potentially unsuccessful outcomes.


Representation of Protein-Sequence Information by Amino Acid Subalphabets

AI Magazine

Within computational biology, algorithms are constructed with the aim of extracting knowledge from biological data, in particular, data generated by the large genome projects, where gene and protein sequences are produced in high volume. In this article, we explore new ways of representing protein-sequence information, using machine learning strategies, where the primary goal is the discovery of novel powerful representations for use in AI techniques. In the case of proteins and the 20 different amino acids they typically contain, it is also a secondary goal to discover how the current selection of amino acids -- which now are common in proteins -- might have emerged from simpler selections, or alphabets, in use earlier during the evolution of living organisms.


Calendar of Events

AI Magazine

NASA Ames Research Center Polish Academy of Sciences URL: www.taai.org.tw/announce/ (PRICAI 2004). (ICKEDS 2004). This book looks at some of the results of the synergy among AI, cognitive science, and education. Examples include virtual students whose misconceptions force students to reflect on their own knowledge, intelligent tutoring systems, and speech recognition technology that helps students learn to read.


AI in the News

AI Magazine

"Over the last decade, This eclectic keepsake provides a sampling to design vision and navigation some jobs have vanished, others are fading of what can be found (with links to the full systems based on the honeybee.... But lots of new ones have appeared. Please key lies in understanding how insects With the help of Toronto Star keep in mind that (1) the mere mention of perceive their world…." "From the Luddites the articles were initially available and thinking.... * Bio-informatician: Not Such collection--updated, hyperlinked, and molecular biology and computer science. The robot scientist developed (www.dailynewstribune.com). TIME online edition from the point of view of the human researcher, has participated in various fund-raising (www.time.com). "President Bush will announce it does so as effectively as a person.... events -- including selling Krispy Kreme later this week a plan to resume One question is, if their robot does doughnuts on Moody Street the day after missions to the Moon and send humans make an important discovery, will it be Thanksgiving and raffling off a new DVD to Mars within 20 years, with international eligible to win a Nobel prize?" player donated by Watch City Appliance. Such a plan is likely ... Students created two robots from to be tremendously expensive, and some January 15: A New Robot Makes a Leap scratch that were not manipulated by remote argue that manned space missions are unnecessary in Brainpower. Philadelphia control, but, rather, programmed to with the level of sophistication Inquirer (www.philly.com). "A new robot is compete in the Botball competition.


The Semantic Web and Language Technology, Its Potential and Practicalities: EUROLAN-2003

AI Magazine

Later in the school, the focus turned to ontologies, which is where the true power of the semantic web lies. EUROLAN lecturers treated its potential in terms of what the topic of ontology development it might--and might not--bring to us in the future. This year's and how great its impact will really start somewhere, somehow, even if school was organized by the Faculty be. Although it is not yet clear what emerges is a variety of ontological of Computer Science at the A. I. Cuza whether the current vision of the semantic stores from which to choose. University of Iasi, the Research Institute web will indeed reach its expectations, The EUROLAN summer school also for Artificial Intelligence at the there are more and more included a workshop on ontologies Romanian Academy in Bucharest, opinions that it represents a major and information extraction, a student and the Department of Computer technological step that will permanently workshop on applied natural Science at Vassar College.


A Personalized System for Conversational Recommendations

Journal of Artificial Intelligence Research

Searching for and making decisions about information is becoming increasingly difficult as the amount of information and number of choices increases. Recommendation systems help users find items of interest of a particular type, such as movies or restaurants, but are still somewhat awkward to use. Our solution is to take advantage of the complementary strengths of personalized recommendation systems and dialogue systems, creating personalized aides. We present a system -- the Adaptive Place Advisor -- that treats item selection as an interactive, conversational process, with the program inquiring about item attributes and the user responding. Individual, long-term user preferences are unobtrusively obtained in the course of normal recommendation dialogues and used to direct future conversations with the same user. We present a novel user model that influences both item search and the questions asked during a conversation. We demonstrate the effectiveness of our system in significantly reducing the time and number of interactions required to find a satisfactory item, as compared to a control group of users interacting with a non-adaptive version of the system.


Representation Dependence in Probabilistic Inference

Journal of Artificial Intelligence Research

Non-deductive reasoning systems are often representation dependent: representing the same situation in two different ways may cause such a system to return two different answers. Some have viewed this as a significant problem. For example, the principle of maximum entropyhas been subjected to much criticism due to its representation dependence. There has, however, been almost no work investigating representation dependence. In this paper, we formalize this notion and show that it is not a problem specific to maximum entropy. In fact, we show that any representation-independent probabilistic inference procedure that ignores irrelevant information is essentially entailment, in a precise sense. Moreover, we show that representation independence is incompatible with even a weak default assumption of independence. We then show that invariance under a restricted class of representation changes can form a reasonable compromise between representation independence and other desiderata, and provide a construction of a family of inference procedures that provides such restricted representation independence, using relative entropy.


IDL-Expressions: A Formalism for Representing and Parsing Finite Languages in Natural Language Processing

Journal of Artificial Intelligence Research

We propose a formalism for representation of finite languages, referred to as the class of IDL-expressions, which combines concepts that were only considered in isolation in existing formalisms. The suggested applications are in natural language processing, more specifically in surface natural language generation and in machine translation, where a sentence is obtained by first generating a large set of candidate sentences, represented in a compact way, and then by filtering such a set through a parser. We study several formal properties of IDL-expressions and compare this new formalism with more standard ones. We also present a novel parsing algorithm for IDL-expressions and prove a non-trivial upper bound on its time complexity.