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A novel model-based heuristic for energy optimal motion planning for automated driving
Ajanovic, Zlatan, Stolz, Michael, Horn, Martin
Predictive motion planning is the key to achieve energy-efficient driving, which is one of the main benefits of automated driving. Researchers have been studying the planning of velocity trajectories, a simpler form of motion planning, for over a decade now and many different methods are available. Dynamic programming has shown to be the most common choice due to its numerical background and ability to include nonlinear constraints and models. Although planning of an optimal trajectory is done in a systematic way, dynamic programming does not use any knowledge about the considered problem to guide the exploration and therefore explores all possible trajectories. A* is a search algorithm which enables using knowledge about the problem to guide the exploration to the most promising solutions first. Knowledge has to be represented in a form of a heuristic function, which gives an optimistic estimate of cost for transitioning to the final state, which is not a straightforward task. This paper presents a novel heuristics incorporating air drag and auxiliary power as well as operational costs of the vehicle, besides kinetic and potential energy and rolling resistance known in the literature. Furthermore, optimal cruising velocity, which depends on vehicle aerodynamic properties and auxiliary power, is derived. Results are compared for different variants of heuristic functions and dynamic programming as well.
Matched Filters for Noisy Induced Subgraph Detection
Sussman, Daniel L., Lyzinski, Vince, Park, Youngser, Priebe, Carey E.
We consider the problem of finding the vertex correspondence between two graphs with different number of vertices where the smaller graph is still potentially large. We propose a solution to this problem via a graph matching matched filter: padding the smaller graph in different ways and then using graph matching methods to align it to the larger network. Under a statistical model for correlated pairs of graphs, which yields a noisy copy of the small graph within the larger graph, the resulting optimization problem can be guaranteed to recover the true vertex correspondence between the networks, though there are currently no efficient algorithms for solving this problem. We consider an approach that exploits a partially known correspondence and show via varied simulations and applications to the Drosophila connectome that in practice this approach can achieve good performance.
Fast Best Subset Selection: Coordinate Descent and Local Combinatorial Optimization Algorithms
Hazimeh, Hussein, Mazumder, Rahul
We consider the canonical $L_0$-regularized least squares problem (aka best subsets) which is generally perceived as a `gold-standard' for many sparse learning regimes. In spite of worst-case computational intractability results, recent work has shown that advances in mixed integer optimization can be used to obtain near-optimal solutions to this problem for instances where the number of features $p \approx 10^3$. While these methods lead to estimators with excellent statistical properties, often there is a price to pay in terms of a steep increase in computation times, especially when compared to highly efficient popular algorithms for sparse learning (e.g., based on $L_1$-regularization) that scale to much larger problem sizes. Bridging this gap is a main goal of this paper. We study the computational aspects of a family of $L_0$-regularized least squares problems with additional convex penalties. We propose a hierarchy of necessary optimality conditions for these problems. We develop new algorithms, based on coordinate descent and local combinatorial optimization schemes, and study their convergence properties. We demonstrate that the choice of an algorithm determines the quality of solutions obtained; and local combinatorial optimization-based algorithms generally result in solutions of superior quality. We show empirically that our proposed framework is relatively fast for problem instances with $p\approx 10^6$ and works well, in terms of both optimization and statistical properties (e.g., prediction, estimation, and variable selection), compared to simpler heuristic algorithms. A version of our algorithm reaches up to a three-fold speedup (with $p$ up to $10^6$) when compared to state-of-the-art schemes for sparse learning such as glmnet and ncvreg.
Artificial Intelligence vs Business Intelligence - Learn 6 Useful Comparison
Business Intelligence is a technology that is used to gather, store, access and analyzes data to help business users in making better decisions, on the other hand, Artificial Intelligence is a way to make a computer, a computer-controlled robot, or a software that think intelligently like humans.Artificial Intelligence is based on the study that how human thinks, learn, decide and work in order to resolve an issue and then using the outcome of this study as a basis of developing intelligent software and systems. It starts from root node and explores neighbor nodes first and moves to the next level neighbor nodes.It provides the shortest path to the solution and can be implemented using FIFO This algorithm is implemented using LIFO(Last in first out)data structure.It creates nodes same as breadth-first search but it differs in only order.In each iteration, it stores the nodes from root to leaf and also it cannot check duplicate nodes. It makes predictions by using Bayes algorithm, which derives probability prediction from the underlying evidence, as observed in data. In this algorithm, sorting is done in increasing cost of the path to a node.It always expands the least cost node.This search is identical to the Breadth-first search if each transition has the same cost.It explores the path in the increasing order of cost. It implements logistic regression for classification of binary targets and linear regression for continuous targets.It supports confidence bounds for prediction probabilities and also supports confidence bounds for prediction. It performs the depth-first search at level-1 and starts over, then executes a complete depth-first search to level 2, and continues till it gets the solution.
Learning From Scratch by Thinking Fast and Slow with Deep Learning and Tree Search
According to dual process theory human reasoning consists of two different kinds of thinking. System 1 is a fast, unconscious and automatic mode of thought, also known as intuition. System 2 is a slow, conscious, explicit and rule-based mode of reasoning that is believed to be an evolutionarily recent process. When learning to complete a challenging planning task, such as playing a board game, humans exploit both processes: strong intuitions allow for more effective analytic reasoning by rapidly selecting interesting lines of play for consideration. Repeated deep study gradually improves intuitions.
Binary Search Algorithms explained using security camera footage
I used to live in a building that had a communal kitchen for over 100 students. As you might imagine, there were almost always dishes that weren't washed in the sink. A group at my school pitched the idea to put up a Nest Cam to catch culprits and call them out on it using the Nest Cam feed. To illustrate my point, let's say you found dirty dishes at 12 pm, and you hadn't been in the kitchen for a day. Think about the way that you would search for the person who left the dishes.
Minimax rates for cost-sensitive learning on manifolds with approximate nearest neighbours
We study the approximate nearest neighbour method for cost-sensitive classification on low-dimensional manifolds embedded within a high-dimensional feature space. We determine the minimax learning rates for distributions on a smooth manifold, in a cost-sensitive setting. This generalises a classic result of Audibert and Tsybakov. Building upon recent work of Chaudhuri and Dasgupta we prove that these minimax rates are attained by the approximate nearest neighbour algorithm, where neighbours are computed in a randomly projected low-dimensional space. In addition, we give a bound on the number of dimensions required for the projection which depends solely upon the reach and dimension of the manifold, combined with the regularity of the marginal.
Mostly Exploration-Free Algorithms for Contextual Bandits
Bastani, Hamsa, Bayati, Mohsen, Khosravi, Khashayar
The contextual bandit literature has traditionally focused on algorithms that address the exploration-exploitation tradeoff. In particular, greedy algorithms that exploit current estimates without any exploration may be sub-optimal in general. However, exploration-free greedy algorithms are desirable in practical settings where exploration may be costly or unethical (e.g., clinical trials). Surprisingly, we find that a simple greedy algorithm can be rate-optimal if there is sufficient randomness in the observed contexts. We prove that this is always the case for a two-armed bandit under a general class of context distributions that satisfy a condition we term covariate diversity. Furthermore, even absent this condition, we show that a greedy algorithm can be rate-optimal with nonzero probability. Thus, standard bandit algorithms may unnecessarily explore. Motivated by these results, we introduce Greedy-First, a new algorithm that uses only observed contexts and rewards to determine whether to follow a greedy algorithm or to explore. We prove that this algorithm is rate-optimal without any additional assumptions on the context distribution or the number of arms. Extensive simulations demonstrate that Greedy-First successfully reduces experimentation and outperforms existing (exploration-based) contextual bandit algorithms such as Thompson sampling or UCB.
KABouM: Knowledge-Level Action and Bounding Geometry Motion Planner
Gaschler, Andre, Petrick, Ronald P. A., Khatib, Oussama, Knoll, Alois
For robots to solve real world tasks, they often require the ability to reason about both symbolic and geometric knowledge. We present a framework, called KABouM, for integrating knowledge-level task planning and motion planning in a bounding geometry. By representing symbolic information at the knowledge level, we can model incomplete information, sensing actions and information gain; by representing all geometric entities-- objects, robots and swept volumes of motions--by sets of convex polyhedra, we can efficiently plan manipulation actions and raise reasoning about geometric predicates, such as collisions, to the symbolic level. At the geometric level, we take advantage of our bounded convex decomposition and swept volume computation with quadratic convergence, and fast collision detection of convex bodies. We evaluate our approach on a wide set of problems using real robots, including tasks with multiple manipulators, sensing and branched plans, and mobile manipulation.
Languages evolve based on the unique requirements of AI applications
The evolution of artificial intelligence (AI) grew with the complexity of the languages available for development. In 1959, Arthur Samuel developed a self-learning checkers program at IBM on an IBM 701 computer using the native instructions of the machine (quite a feat given search trees and alpha-beta pruning). But today, AI is developed using various languages, from Lisp to Python to R. This article explores the languages that evolved for AI and machine learning. The programming languages that are used to build AI and machine learning applications vary. Each application has its own constraints and requirements, and some languages are better than others in particular problem domains.