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 Spatial Reasoning


How Does a Mathematician's Brain Differ from That of a Mere Mortal?

#artificialintelligence

Alan Turing, Albert Einstein, Stephen Hawking, John Nash--these "beautiful" minds never fail to enchant the public, but they also remain somewhat elusive. How do some people progress from being able to perform basic arithmetic to grasping advanced mathematical concepts and thinking at levels of abstraction that baffle the rest of the population? Neuroscience has now begun to pin down whether the brain of a math wiz somehow takes conceptual thinking to another level. Specifically, scientists have long debated whether the basis of high-level mathematical thought is tied to the brain's language-processing centers--that thinking at such a level of abstraction requires linguistic representation and an understanding of syntax--or to independent regions associated with number and spatial reasoning. In a study published this week in Proceedings of the National Academy of Sciences, a pair of researchers at the INSERM–CEA Cognitive Neuroimaging Unit in France reported that the brain areas involved in math are different from those engaged in equally complex nonmathematical thinking.


Extracting Generalizable Spatial Features from Smart Phones Datasets

AAAI Conferences

This paper is part of the effort to develop assistive smart homes able to monitor the daily life activity of a resident and provide punctual assistance when necessary. One of the limitations of assistive smart homes is the fact that it cannot assist the resident when he is going out. Because of this, many researchers are working on wearable sensors to keep track of the activities outside the home. Our lab proposes to instead focus on smart phones which are a cheap alternative that many persons already carry in their daily life. While most algorithms used in the smart home can be exploited, smart phones generate spatial information from the GPS that do not scale very well. The goal of this paper is to initiate a discussion on spatial features and their exploitation for data mining of smart phones datasets.


Countering Quantitative Alienation with Geographic Codified Narrative

@machinelearnbot

Codified narrative is the product of converting human-friendly narrative into computer-friendly code. In past blogs, I discussed my own approach towards this process of codification. Here, I will be covering the idea of spatial, temporal, and contextual distribution of codified narrative. I have never suggested that narrative can or should be used in place of quantitative data. However, I have reflected on how the quantitative regime has tended to dominate discourse; this has perhaps led to data being contextually constrained or deprived. Geography is a type of context that can shape the extent to which people interact with the world. Space provides a medium to distribute resources. It can be involved in forced confinement. An office full of cubicles demonstrates control and dominance over space.


R Spatial Representation

@machinelearnbot

Spatial Visualization Using R: One of the less understood aspects of R is in spatial data visualization. The below article will outline two case studies on using R to spatially visualize data. Our first step is figuring out how to use the Census API within R. Given below are the key data Source Details from the Census ACS Data We use the acs.lookup function & use the keywords to find the required data across all ACS tables. For example, the following are the search results for the keywords owner, occupied, and median. Using the Choroplethr package make it really easy to create thematic maps in R.


Knowledge Representation in Probabilistic Spatio-Temporal Knowledge Bases

Journal of Artificial Intelligence Research

We represent knowledge as integrity constraints in a formalization of probabilistic spatio-temporal knowledge bases. We start by defining the syntax and semantics of a formalization called PST knowledge bases. This definition generalizes an earlier version, called SPOT, which is a declarative framework for the representation and processing of probabilistic spatio-temporal data where probability is represented as an interval because the exact value is unknown. We augment the previous definition by adding a type of non-atomic formula that expresses integrity constraints. The result is a highly expressive formalism for knowledge representation dealing with probabilistic spatio-temporal data. We obtain complexity results both for checking the consistency of PST knowledge bases and for answering queries in PST knowledge bases, and also specify tractable cases. All the domains in the PST framework are finite, but we extend our results also to arbitrarily large finite domains.


Deploying PAWS: Field Optimization of the Protection Assistant for Wildlife Security

AAAI Conferences

Poaching is a serious threat to the conservation of key species and whole ecosystems. While conducting foot patrols is the most commonly used approach in many countries to prevent poaching, such patrols often do not make the best use of limited patrolling resources. To remedy this situation, prior work introduced a novel emerging application called PAWS (Protection Assistant for Wildlife Security); PAWS was proposed as a game-theoretic (``security games'') decision aid to optimize the use of patrolling resources. This paper reports on PAWS's significant evolution from a proposed decision aid to a regularly deployed application, reporting on the lessons from the first tests in Africa in Spring 2014, through its continued evolution since then, to current regular use in Southeast Asia and plans for future worldwide deployment. In this process, we have worked closely with two NGOs (Panthera and Rimba) and incorporated extensive feedback from professional patrolling teams. We outline key technical advances that lead to PAWS's regular deployment: (i) incorporating complex topographic features, e.g., ridgelines, in generating patrol routes; (ii) handling uncertainties in species distribution (game theoretic payoffs); (iii) ensuring scalability for patrolling large-scale conservation areas with fine-grained guidance; and (iv) handling complex patrol scheduling constraints.


Relations Between Spatial Calculi About Directions and Orientations

Journal of Artificial Intelligence Research

Qualitative spatial descriptions characterize essential properties of spatial objects or configurations by relying on relative comparisons rather than measuring. Typically, in qualitative approaches only relatively coarse distinctions between configurations are made. Qualitative spatial knowledge can be used to represent incomplete and underdetermined knowledge in a systematic way. This is especially useful if the task is to describe features of classes of configurations rather than individual configurations. Although reasoning with them is generally NP-hard (even IR-complete), relative directions are important because they play a key role in human spatial descriptions and there are several approaches how to represent them using qualitative methods. In these approaches directions between spatial locations can be expressed as constraints over infinite domains, e.g. the Euclidean plane. The theory of relation algebras has been successfully applied to this field. Viewing relation algebras as universal algebras and applying and modifying standard tools from universal algebra in this work, we (re)define notions of qualitative constraint calculus, of homomorphism between calculi, and of quotient of calculi.Based on this method we derive important properties for spatial calculi from corresponding properties of related calculi. From a conceptual point of view these formal mappings between calculi are a means to translate between different granularities.


A Unified Framework for Human-Robot Knowledge Transfer

AAAI Conferences

Transferring knowledge is a vital skill between humans for efficiently learning a new concept. In a perfect system, a human demonstrator can teach a robot a new task by using natural language and physical gestures. The robot would gradually accumulate and refine its spatial, temporal, and causal understanding of the world. The knowledge can then be transferred back to another human, or further to another robot. The implications of effective human to robot knowledge transfer include the compelling opportunity of a robot acting as the teacher, guiding humans in new tasks. The technical difficulty in achieving a robot implementation Figure 1: The robot autonomously performs a cloth folding of this caliber involves both an expressive knowledge task after learning from a human demonstration.


Automated Decomposition of Game Maps

AAAI Conferences

Video game worlds are getting increasingly large and complex. This poses challenges to the game AI for both pathfinding and strategic decisions, not least in real-time strategy games. One way to alleviate the problem is to manually pre-label the game maps with information about regions and critical choke points, which the game AI can then take advantage of. We present a method for automatically decomposing game maps into non-uniform sized regions. The method uses a flooding algorithm at its core and has the benefit, in addition to its effectiveness, to be relatively intuitive both conceptually and in implementing. Empirical evaluation on game maps shows that the automatic decomposition results in intuitive regions of a comparable standard to human-made labeling. Furthermore, we show that our automatic decomposition, when used by a pathfinding algorithm capable of taking advantage of pre-labeled regions, significantly improves search effectiveness.


Sparse Pseudo-input Local Kriging for Large Non-stationary Spatial Datasets with Exogenous Variables

arXiv.org Machine Learning

Gaussian process (GP) regression is a powerful tool for building predictive models for spatial systems. However, it does not scale efficiently for large datasets. Particularly, for high-dimensional spatial datasets, i.e., spatial datasets that contain exogenous variables, the performance of GP regression further deteriorates. This paper presents the Sparse Pseudo-input Local Kriging (SPLK) which approximates the full GP for spatial datasets with exogenous variables. SPLK employs orthogonal cuts which decompose the domain into smaller subdomains and then applies a sparse approximation of the full GP in each subdomain. We obtain the continuity of the global predictor by imposing continuity constraints on the boundaries of the neighboring subdomains. The domain decomposition scheme applies independent covariance structures in each region, and as a result, SPLK captures heterogeneous covariance structures. SPLK achieves computational efficiency by utilizing sparse approximation in each subdomain which enables SPLK to accommodate large subdomains that contain many data points and possess a homogenous covariance structure. We Apply the proposed method to real and simulated datasets. We conclude that the combination of orthogonal cuts and sparse approximation makes the proposed method an efficient algorithm for high-dimensional large spatial datasets.