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Say Cheese! Experiences with a Robot Photographer
Byers, Zachary, Dixon, Michael, Smart, William D., Grimm, Cindy M.
This model makes system debugging significantly easier, because we know We introduced a sensor abstraction layer to exactly what each sensor reading is at every separate the task layer from concerns about point in the computation; something that physical sensing devices. We process the sensor would not be the case if we were reading from information (from the laser rangefinder in this the sensors every time a reading was used in a application) into distance measurements from calculation. This model also allows us to inject the center of the robot, thus allowing consideration modified sensor readings into the system, as of sensor error models and performance described in the next section.
Qualitative Spatial Reasoning about Sketch Maps
Forbus, Kenneth D., Usher, Jeffrey, Chapman, Vernell
Sketch maps are an important spatial representation used in many geospatial-reasoning tasks. This article describes techniques we have developed that enable software to perform humanlike reasoning about sketch maps. We illustrate the utility of these techniques in the context of nuSketch Battlespace, a research system that has been successfully used in a variety of experiments. After an overview of the nuSketch approach and nuSketch Battlespace, we outline the representations of glyphs and sketches and the nuSketch spatial reasoning architecture. We describe the use of qualitative topology and Voronoi diagrams to construct spatial representations, and explain how these facilities are combined with analogical reasoning to provide a simple form of enemy intent hypothesis generation.
AI in the News
This eclectic keepsake provides a sampling was initially inspired by science fiction, "[iRobot Chairman Helen] Greiner believes'One of what can be found (with links to the full the movie may influence a new generation She said the R2D2 robot's humanlike She went on to the articles were initially available inventions were predicted by those sort of MIT where she earned undergraduate and online and without charge, few things that writers. In terms of the capabilities that graduate degrees in mechanical engineering, good last forever; and (4) the AI in the News we get in modern computers, they could electrical engineering and computer collection--updated, hyperlinked, and see some of that. What I find so interesting science. 'It takes all three (disciplines) and archived--can be found by going to is that we start with these ideas which they must all come together in robotics,' www.aaai.org/aitopics/html/current.html. June 10, "In the war on terror, University about robots programmed to think on Breazeal of the Massachusetts Institute of professor Robin Murphy finds herself a New Jersey.
A Comprehensive Trainable Error Model for Sung Music Queries
Meek, C. J., Birmingham, W. P.
We propose a model for errors in sung queries, a variant of the hidden Markov model (HMM). This is a solution to the problem of identifying the degree of similarity between a (typically error-laden) sung query and a potential target in a database of musical works, an important problem in the field of music information retrieval. Similarity metrics are a critical component of `query-by-humming' (QBH) applications which search audio and multimedia databases for strong matches to oral queries. Our model comprehensively expresses the types of {m error} or variation between target and query: cumulative and non-cumulative local errors, transposition, tempo and tempo changes, insertions, deletions and modulation. The model is not only expressive, but automatically trainable, or able to learn and generalize from query examples. We present results of simulations, designed to assess the discriminatory potential of the model, and tests with real sung queries, to demonstrate relevance to real-world applications.
Universal Convergence of Semimeasures on Individual Random Sequences
Hutter, Marcus, Muchnik, Andrej
Solomonoff's central result on induction is that the posterior of a universal semimeasure M converges rapidly and with probability 1 to the true sequence generating posterior mu, if the latter is computable. Hence, M is eligible as a universal sequence predictor in case of unknown mu. Despite some nearby results and proofs in the literature, the stronger result of convergence for all (Martin-Loef) random sequences remained open. Such a convergence result would be particularly interesting and natural, since randomness can be defined in terms of M itself. We show that there are universal semimeasures M which do not converge for all random sequences, i.e. we give a partial negative answer to the open problem. We also provide a positive answer for some non-universal semimeasures. We define the incomputable measure D as a mixture over all computable measures and the enumerable semimeasure W as a mixture over all enumerable nearly-measures. We show that W converges to D and D to mu on all random sequences. The Hellinger distance measuring closeness of two distributions plays a central role.
On the Convergence Speed of MDL Predictions for Bernoulli Sequences
We consider the Minimum Description Length principle for online sequence prediction. If the underlying model class is discrete, then the total expected square loss is a particularly interesting performance measure: (a) this quantity is bounded, implying convergence with probability one, and (b) it additionally specifies a `rate of convergence'. Generally, for MDL only exponential loss bounds hold, as opposed to the linear bounds for a Bayes mixture. We show that this is even the case if the model class contains only Bernoulli distributions. We derive a new upper bound on the prediction error for countable Bernoulli classes. This implies a small bound (comparable to the one for Bayes mixtures) for certain important model classes. The results apply to many Machine Learning tasks including classification and hypothesis testing. We provide arguments that our theorems generalize to countable classes of i.i.d. models.
Ordinal and Probabilistic Representations of Acceptance
Dubois, D., Fargier, H., Prade, H.
An accepted belief is a proposition considered likely enough by an agent, to be inferred from as if it were true. This paper bridges the gap between probabilistic and logical representations of accepted beliefs. To this end, natural properties of relations on propositions, describing relative strength of belief are augmented with some conditions ensuring that accepted beliefs form a deductively closed set. This requirement turns out to be very restrictive. In particular, it is shown that the sets of accepted belief of an agent can always be derived from a family of possibility rankings of states. An agent accepts a proposition in a given context if this proposition is considered more possible than its negation in this context, for all possibility rankings in the family. These results are closely connected to the non-monotonic 'preferential' inference system of Kraus, Lehmann and Magidor and the so-called plausibility functions of Friedman and Halpern. The extent to which probability theory is compatible with acceptance relations is laid bare. A solution to the lottery paradox, which is considered as a major impediment to the use of non-monotonic inference is proposed using a special kind of probabilities (called lexicographic, or big-stepped). The setting of acceptance relations also proposes another way of approaching the theory of belief change after the works of Gärdenfors and colleagues. Our view considers the acceptance relation as a primitive object from which belief sets are derived in various contexts.
Semiclassical Neural Network
We have constructed a simple semiclassical model of neural network where neurons have quantum links with one another in a chosen way and affect one another in a fashion analogous to action potentials. We have examined the role of stochasticity introduced by the quantum potential and compare the system with the classical system of an integrate-and-fire model by Hopfield. Average periodicity and short term retentivity of input memory are noted.
RoboCup-2003: New Scientific and Technical Advances
Pagello, Enrico, Menegatti, Emanuele, Bredenfel, Ansgar, Costa, Paulo, Christaller, Thomas, Jacoff, Adam, Polani, Daniel, Riedmiller, Martin, Saffiotti, Alessandro, Sklar, Elizabeth, Tomoichi, Takashi
This article reports on the RoboCup-2003 event. RoboCup is no longer just the Soccer World Cup for autonomous robots but has evolved to become a coordinated initiative encompassing four different robotics events: (1) Soccer, (2) Rescue, (3) Junior (focused on education), and (4) a Scientific Symposium. RoboCup-2003 took place from 2 to 11 July 2003 in Padua (Italy); it was colocated with other scientific events in the field of AI and robotics. In this article, in addition to reporting on the results of the games, we highlight the robotics and AI technologies exploited by the teams in the different leagues and describe the most meaningful scientific contributions.