36905391
A note on the use of probabilities by mechanical learners
We raise the following problem: in a probabilistic context, is it always fruitful for a machine to compute probabilities? The question is made precise in a paradigm of the limit-identification kind, where a learner must discover almost surely whether an infinite sequence of heads and tails belongs to an effective subset S of the Cantor space. In this context, a successful strategy for an ineffective learner is to compute, at each stage, the conditional probability that he is faced with an element of S, given the data received so far. We show that an effective learner should not proceed this way in all circumstances. Indeed, even if he gets an optimal description of a set S, and even if some machine can always compute the conditional probability for S given any data, an effective learner optimizes his inductive competence only if he does not compute the relevant probabilities. We conclude that the advice “compute probabilities whenever you can” should sometimes be received with caution in the context of machine learning.
15807941
Human Discovery and Machine Learning
This article studies machine learning paradigms from the point of view of human cognition. Indeed, conceptions in both machine learning and human learning evolved from a passive to an active conception of learning. Our objective is to provide an interaction protocol suited to both humans and machines to enable assisting human discoveries by learning machines. We identify the limitations of common machine learning paradigms in the context of scientific discovery, and we propose an extension inspired by game theory and multiagent systems. We present individual cognitive aspects of this protocol as well as social considerations, and we relate encouraging results concerning a game implementing it.
37212285
Quantification over names and modalities
38643151
Learning from Each Other
Since its inception, the field of machine learning has seen the advent of several learning paradigms, designed to frame the issues central to the learning activity, provide effective learning methods, and investigate the power and limitations inherent to the process of successful learning. In this article, we propose a formalization that underlies the key concepts of many such paradigms and discuss their relevance to scientific discovery, with the aim of assessing what scientists can expect from machines designed to assist them in their quest for the discovery of valid laws. We illustrate the formalization on several variations of a card game, and highlight the differences that paradigms impose on learners, as well as the assumptions they make on the nature of the learning process. We then use the formalization to describe a multi-agent interaction protocol, that has been inspired by these paradigms and that has been validated recently on some groups of agents. Finally, we propose extensions to this protocol.
638940
On the data consumption benefits of accepting increased uncertainty
In the context of learning paradigms of identification in the limit, we address the question: why is uncertainty sometimes desirable? We use mind change bounds on the output hypotheses as a measure of uncertainty, and interpret 'desirable' as reduction in data memorization, also defined in terms of mind change bounds. The resulting model is closely related to iterative learning with bounded mind change complexity, but the dual use of mind change bounds - for hypotheses and for data - is a key distinctive feature of our approach. We show that situations exists where the more mind changes the learner is willing to accept, the lesser the amount of data it needs to remember in order to converge to the correct hypothesis. We also investigate relationships between our model and learning from good examples, set-driven, monotonic and strong-monotonic learners, as well as class-comprising versus class-preserving learnability.
39139980
On Sufficient Conditions for Learnability of Logic Programs from Positive Data
Shinohara, Arimura, and Krishna Rao have shown learnability in the limit of minimal models of classes of logic programs from positive only data. In most cases, these results involve logic programs in which the "size" of the head yields a bound on the size of the body literals. However, when local variables are present, such a bound on body literal size cannot directly be ensured. The above authors achieve such a restriction using technical notions like mode and linear inequalities. The present paper develops a conceptually clean framework where the behavior of local variables is controlled by nonlocal ones. It is shown that for certain classes of logic programs, learnablity from positive data is equivalent to limiting identification of bounds for the number of clauses and the number of local variables. This reduces the learning problem finding two integers. This cleaner framework generalizes all the known results and establishes learnability of new classes.
1889407
Sensitivity Analysis and Other Improvements to Tailored Combinatorial Library Design
"Tailoring" combinatorial libraries was developed several years ago as a very general and intuitive method to design diverse compound collections while controlling the profile of other pharmaceutically relevant properties. The candidate substituents were assigned to "categorical bins" according to their properties, and successive steps of D-optimal design were performed to generate diverse substituent sets consistent with required membership quotas from each bin. This serial algorithm was expedient to implement from existing D-optimal design codes, but was order-dependent and did not generally locate the very best possible design. A new "parallel" Fedorov search algorithm has now been implemented that can find the most diverse property-tailored design. An ambiguous mass penalty has been added, whereby most duplicate masses can be eliminated with little loss of library diversity. Sensitivity analysis has also been added to quantitatively explore the diversity trade-offs due to increasing or decreasing each specific kind of bias.
51977174
A Memory Aware High Level Synthesis Too
We introduce a new approach to take into account the memory architecture and the memory mapping in High- Level Synthesis for data intensive applications. We formalize the memory mapping as a set of constraints for the synthesis, and defined a Memory Constraint Graph and an accessibility criterion to be used in the scheduling step. We use a memory mapping file to include those memory constraints in our HLS tool GAUT. It is possible, with the help of GAUT, to explore a wide range of solutions, and to reach a good tradeoff between time, power-consumption, and area.
60978385
Power Consumption Characterization and Modeling of Embedded Memories in XILINX VIRTEX 400E FPGA
To increase their flexibility, latest FPGA devices integrate processors, arithmetics elements and memories; but these programmable circuits have a significant power consuming, which grows up at each process generation. Then it is necessary to develop reliable high-level power consumption models in order to estimate and reduce the power budget as soon as possible in the design flow. Among the FPGA modeling methods, none has integrated the embedded memory yet. We propose here a power model of embedded memory for the Xilinx Virtex 400E based on physical measurements combined with algorithmic and architectural parameters. This simple model is validated in comparison to Xilinx's estimation tool XPOWER and an example of memory architecture design illustrates the interest of such an approach.
17460903
A memory aware high level synthesis tool
We introduce a new approach to take into account the memory architecture and the memory mapping in high-level synthesis for data intensive applications. We formalize the memory mapping as a set of constraints for the synthesis, and defined a memory constraint graph and an accessibility criterion to be used in the scheduling step. We use a memory mapping file to include those memory constraints in our HLS tool GAUT. It is possible, with the help of GAUT, to explore a wide range of solutions, and to reach a good tradeoff between time, power-consumption, and area.
62212474
A design flow dedicated to multi-mode architectures for DSP applications
This paper addresses the design of multi-mode architectures for digital signal processing applications. We present a dedicated design flow and its associated high-level synthesis tool, named GAUT. Given a unified description of a set of time-wise mutually exclusive tasks and their associated throughput constraints, a single RTL hardware architecture optimized in area is generated. In order to reduce the register, steering logic (multiplexers) and controller (decoding logic) complexities, we propose a joint-scheduling algorithm which maximizes the similarities between control steps and specific binding approaches for both functional units and storage elements which maximize the similarities between the datapaths. We show through a set of test cases that our approach offers significant area saving relative to the state-of-the-art.