Goto

Collaborating Authors

 Government


Strategic Voting and Strategic Candidacy

AAAI Conferences

Models of strategic candidacy analyze the incentives of candidates to run in an election. Most work on this topic assumes that strategizing only takes place among candidates, whereas voters vote truthfully. In this paper, we extend the analysis to also include strategic behavior on the part of the voters. (We also study cases where only candidates or only voters are strategic.) We consider two settings in which strategic voting is well-defined and has a natural interpretation: majority-consistent voting with single-peaked preferences and voting by successive elimination. In the former setting, we analyze the type of strategic behavior required in order to guarantee desirable voting outcomes. In the latter setting, we determine the complexity of computing the set of potential outcomes if both candidates and voters act strategically.


Toxicity Prediction using Deep Learning

arXiv.org Machine Learning

Everyday we are exposed to various chemicals via food additives, cleaning and cosmetic products and medicines -- and some of them might be toxic. However testing the toxicity of all existing compounds by biological experiments is neither financially nor logistically feasible. Therefore the government agencies NIH, EPA and FDA launched the Tox21 Data Challenge within the "Toxicology in the 21st Century" (Tox21) initiative. The goal of this challenge was to assess the performance of computational methods in predicting the toxicity of chemical compounds. State of the art toxicity prediction methods build upon specifically-designed chemical descriptors developed over decades. Though Deep Learning is new to the field and was never applied to toxicity prediction before, it clearly outperformed all other participating methods. In this application paper we show that deep nets automatically learn features resembling well-established toxicophores. In total, our Deep Learning approach won both of the panel-challenges (nuclear receptors and stress response) as well as the overall Grand Challenge, and thereby sets a new standard in tox prediction.


Bayesian Optimization of Text Representations

arXiv.org Machine Learning

When applying machine learning to problems in NLP, there are many choices to make about how to represent input texts. These choices can have a big effect on performance, but they are often uninteresting to researchers or practitioners who simply need a module that performs well. We propose an approach to optimizing over this space of choices, formulating the problem as global optimization. We apply a sequential model-based optimization technique and show that our method makes standard linear models competitive with more sophisticated, expensive state-of-the-art methods based on latent variable models or neural networks on various topic classification and sentiment analysis problems. Our approach is a first step towards black-box NLP systems that work with raw text and do not require manual tuning.


Effectiveness of Probability Perception Modeling and Defender Strategy Generation Algorithms in Repeated Stackelberg Games: An Initial Report

AAAI Conferences

While human behavior models based on repeated Stackelberg games have been proposed for domains such as "wildlife crime" where there is repeated interaction between the defender and the adversary, there has been no empirical study with human subjects to show the effectiveness of such models. This paper presents an initial study based on extensive human subject experiments with participants on Amazon Mechanical Turk (AMT). Our findings include: (i) attackers may view the defender’s coverage probability in a non-linear fashion; specifically it follows an S-shaped curve, and (ii) there are significant losses in defender utility when strategies generated by existing models are deployed in repeated Stackelberg game settings against human subjects.


Estimating Reduced Consumption for Dynamic Demand Response

AAAI Conferences

Growing demand is straining our existing electricity generation facilities and requires active participation of the utility and the consumers to achieve energy sustainability. One of the most effective and widely used ways to achieve this goal in the smart grid is demand response (DR), whereby consumers reduce their electricity consumption in response to a request sent from the utility whenever it anticipates a peak in demand. To successfully plan and implement demand response, the utility requires reliable estimate of reduced consumption during DR. This also helps in optimal selection of consumers and curtailment strategies during DR. While much work has been done on predicting normal consumption, reduced consumption prediction is an open problem that is under-studied. In this paper, we introduce and formalize the problem of reduced consumption prediction, and discuss the challenges associated with it. We also describe computational methods that use historical DR data as well as pre-DR conditions to make such predictions. Our experiments are conducted in the real-world setting of a university campus microgrid, and our preliminary results set the foundation for more detailed modeling.


Two Algorithms for the Movements of Robotic Bodyguard Teams

AAAI Conferences

In this paper we consider a scenario where one or more robotic bodyguards are protecting an important individual (VIP) moving in a public space against harassment or harm from unarmed civilians. In this scenario, the main objective of the robots is to position themselves such that at any given moment they provide maximum physical cover for the VIP. The robots need to follow the VIP in its movement and take into account the movements of the civilians as well. The environment can also contain obstacles which present challenges to movement but also provide natural cover. We designed two algorithms for the movement of the bodyguard robots: Threat Vector Resolution (TVR) for a single robot and Quadrant Load Balancing (QLB) for teams of bodyguard robots. We evaluated the proposed approaches against rigid formations in a simulation study.


A Solution Alternative to Achieve Parcel Connectivity in the Dynamic Reserve Design Problem

AAAI Conferences

The DNR is able to purchase lands and engage in conservation easements, but there is considerable uncertainty (for the Conservation reserve design is the problem of selecting reasons enumerated above) about which lands to target, and parcels of land such that the assembled set maximizes when. Furthermore, for any parcel that is protected through some criterion pertaining to the conservation of species or purchase or easement, DNR encumbers a responsibility to natural communities (Williams, ReVelle, and Levin 2005).


Agent Partitioning with Reward/Utility-Based Impact

AAAI Conferences

Reinforcement learning with reward shaping is a well established but often computationally expensive approach to large multiagent systems. Agent partitioning can reduce this computational complexity by treating each partition of agents as an independent problem. We introduce a novel agent partitioning approach called Reward/Utility-Based Impact (RUBI). RUBI finds an effective partitioning of agents while requiring no prior domain knowledge, improves performance by discovering a non-trivial agent partitioning, and leads to faster simulations. We test RUBI in the Air Traffic Flow Management Problem (ATFMP), where there are tens of thousands of aircraft affecting the system and no obvious similarity metric between agents. When partitioning with RUBI in the ATFMP, there is a 37% increase in performance, with a 510x speed increase over non-partitioning approaches. Additionally, RUBI matches the performance of the current domain-dependent ATFMP gold standard using no prior knowledge and with 10% faster performance.


Self-Driving Aircraft Towing Vehicles: A Preliminary Report

AAAI Conferences

We introduce an application of self-driving vehicle technology to the problem of towing aircraft at busy airports from gate to runway and runway to gate. Autonomous towing can be supervised by human ramp- or ATC controllers, pilots, or ground crew. The controllers provide route information to the tugs, assisted by an automated route planning system. The planning system and tower and ground controllers work in conjunction with the tugs to make tactical decisions during operations to ensure safe and effective taxiing in a highly dynamic environment. We argue here for the potential for significantly reducing fuel emissions, fuel costs, and community noise, while addressing the added complexity of air terminal operations by increasing efficiency and reducing human workload. This paper describes work-in-progress for developing concepts and capabilities for autonomous engines-off taxiing using towing vehicles.


Efficient Appliances Recognition in Smart Homes Based on Active and Reactive Power, Fast Fourier Transform and Decision Trees

AAAI Conferences

Western societies are facing demographic challenges due the rapid aging of their population. In this context, economic and social issues are emerging, such as an increasing number of elderly in need of home cares and a shortage of caregivers. Smart home technology has imposed itself as a potential avenue of solution to these important issues. Its goal is to provide adapted assistance to a semi-autonomous resident in the form of hints, suggestions, reminders, and to take preventive actions, for instance turning off the oven, in the case of an emergency. The main scientific challenge related to this kind of assistance concerns the problem of recognizing, in real time, of the on-going activities of the resident in order to provide punctual guidance for the completion of everyday tasks. In the literature, the majority of the proposed solutions for activity recognition exploit a complex and expensive network of intrusive sensors (i.e. infrared, radio-identification, electromagnetic, pressure, cameras, etc.). A recent and innovative way of performing activity recognition is based on the monitoring of electrical household appliances by analyzing the electrical signals solely at the main panel. This approach is less intrusive and required only one sensor. In this paper, we present new advancements in that field, which take the form of an efficient method for recognizing electrical appliances within smart home based on the analysis of the features of the load signatures (active and reactive power, FFT) and on the use of the C4.5 algorithm to extract decision trees. This method has been implemented and tested in real smart home infrastructure showing that it is economical, simple and efficient.