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Quality Control in Crowdsourcing: An Objective Measurement Approach to Identifying and Correcting Rater Effects in the Social Evaluation of Products and Services

AAAI Conferences

Crowdsourcing requires new strategies to evaluate the workers involved as well as the quality of workersโ€™ output. Using customer feedback data, we introduce multi-facetted Rasch scaling as an evaluation technique to assess the contributions of workers and products simultaneously within a single coherent measurement framework. Based on a data set of about 250,000 customers who rated nearly 115,000 products, for a total of nearly 3 million cases, we found that product ratings reflect almost as much the existence of stable rater differences as they are indicative of the productsโ€™ properties. We illustrate how Rasch scaling provides extensive quality control mechanisms; as well we show how aberrant workers and products can be identified so that appropriate feedback and/or corrective actions can be initiated.


Efficient Crowdsourcing With Stochastic Production

AAAI Conferences

A principal seeks production of a good within a limited time-frame with a hard deadline, after which any good procured has no value. There is inherent uncertainty in the production process, which in light of the deadline may warrant simultaneous production of multiple goods by multiple producers despite there being no marginal value for extra goods beyond the maximum quality good produced. This motivates a crowdsourcing model of procurement. We address efficient execution of such procurement from a social planner's perspective, taking account of and optimally balancing the value to the principal with the costs to producers (modeled as effort expenditure) while, crucially, contending with self-interest on the part of all players. A solution to this problem involves both an algorithmic aspect that determines an optimal effort level for each producer given the principal's value, and also an incentive mechanism that achieves equilibrium implementation of the socially optimal policy despite the principal privately observing his value, producers privately observing their skill levels and effort expenditure, and all acting only to maximize their own individual welfare. In contrast to popular "winner take all" contests, the efficient mechanism we propose involves a payment to every producer that expends non-zero effort in the efficient policy.


Distributed Aggregation in the Presence of Uncertainty: A Statistical Physics Approach

AAAI Conferences

We present a statistical physics inspired approach to modeling, analysis, and design of distributed aggregation control policies for teams of homogeneous and heterogeneous robots. We assume high-level agent behavior can be described as a sequential composition of lower-level behavioral primitives. Aggregation or division of the collective into distinct clusters is achieved by developing a macroscopic description of the ensemble dynamics. The advantages of this approach are twofold: 1) the derivation of a low dimensional but highly predictive description of the collective dynamics and 2) a framework where interaction uncertainties between the low-level components can be explicitly modeled and control. Additionally, classical dynamical systems theory and control theoretic techniques can be used to analyze and shape the collective dynamics of the system. We consider the aggregation problem for homogeneous agents into clusters located at distinct regions in the workspace and discuss the extension to heterogeneous teams of autonomous agents. We show how a macroscopic model of the aggregation dynamics can be derived from agent-level behaviors and discuss the synthesis of distributed coordination strategies in the presence of uncertainty.


Autonomous Skills Creation and Integration in Robotics

AAAI Conferences

The fragmentation of research in AI and robotics has created a vast repertoire of skills a robot could be equipped with but that must be manually integrated to form a complex action. We propose a novel evolutionary algorithm that aims at autonomously integrating, adapting and creating new actions by re-using skills that are either externally provided or previously generated. Complex actions are created by instantiating a Finite State Automaton and new skills are created using fully recurrent neural networks. We validated our approach in two scenarios, i.e. exploration and moving to pre-grasp positions. Our experiments show that complex actions can be created by composing independently developed skills. The results have been applied and tested with a real robot in a variety of scenarios.


Integration of Online Learning into HTN Planning for Robotic Tasks

AAAI Conferences

This paper extends hierarchical task network (HTN) planning with lightweight learning, considering that in robotics, actions have a non-zero probability of failing. Our work applies to A*-based HTN planners with lifting. We prove that the planner finds the plan of maximal expected utility, while retaining its lifting capability and efficient heuristic-based search. We show how to learn the probabilities online, which allows a robot to adapt by replanning on execution failures. The idea behind this work is to use the HTN domain to constrain the space of possibilities, and then to learn on the constrained space in a way requiring few training samples, rendering the method applicable to autonomous mobile robots.


Social Network Analysis on the Interaction and Collaboration Behavior among Web Services

AAAI Conferences

Service-Oriented Computing (SOC) has received much interest due to its potential to tackle many adaptive system architecture issues that were previously hard to overcome by other computing paradigms. However, it has been facing great difficulty in quickly discovering and dynamically combing available Web services to satisfy given request on-demand. Most of the current researches concentrated o n the semantic model for service discovery, composition, and so on. But there are few studies concerned the intrinsic pattern and law of the service interactions and relationships. To achiev e the vision of SOC in heterogeneous and open environment, in our opinion, not only the semantics of individual Web service but also the interactions and relationships among Web services are needed to be considered seriously. In this paper, beginning with combining Semantic Web and social networking technology within SOC paradigm, we study associations between Web services, mine the relationships among services to design and build Service Network (SN), anal y z e the structural and social characteristics and complexity of SN to reveal the user interests, business requests, information and data flow and direction. In short, we would like to reassess and reconsider the SOC paradigm from the network perspective, through finding new knowledge to build new theoretical basis and approach which can be used to guide and promote the service discovery, composition, and so on, in SOC paradigm.


A Semantic Metadirectory of Services Based on Web Mining Techniques

AAAI Conferences

In the current web, developers are able to create new applications by composing already existing services from third-party vendors. However, the vast amount of choices, technologies and repositories can make it a tedious task. This paper describes a semantic metadirectory of services that helps in the process of discovering services. We propose a semantic service discovery process and description of existing service repositories, such as Programmable Web and Yahoo Pipes, which are two service repositories which provide plenty of services that can be reused by developers to build new web applications. The challenges behind integrating these repositories involved the problems of defining a common model, identifying relevant data and integrating and ranking the extracted data.


Autonomous Agents Research in Robotics: A Report from the Trenches

AAAI Conferences

This paper surveys research in robotics in the AAMAS (Au- tonomous Agents and Multi-Agent Systems) community. It argues that the autonomous agents community can, and has, impact on robotics. Moreover, it argues that agents re- searchers should proactively seek to impact the robotics com- munity, to prevent independent re-discovery of known results, and to benefit autonomous agents science. To support these claims, I provide evidence from my own research into multi- robot teams, and from othersโ€™.


Robotic Sensor Networks for Environmental Monitoring

AAAI Conferences

Robotic Sensor Networks composed of robots and wireless sensing devices hold the potential to revolutionize environmental sciences by enabling researchers to collect data across expansive environments, over long, sustained periods of time. We report progress on building such systems for two applications. The first application is on monitoring invasive fish (common carp) in inland lakes. In the second application, the robots act as data mules and collect data from sparsely deployed wireless sensors.


Towards Optimal Patrol Strategies for Fare Inspection in Transit Systems

AAAI Conferences

In some urban transit systems, passengers are legally required to purchase tickets before entering but are not physically forced to do so. Instead, patrol units move about through the transit system, inspecting tickets of passengers, who face fines for fare evasion. This setting yields the problem of computing optimal patrol strategies satisfying certain temporal and spacial constraints, to deter fare evasion and hence maximize revenue. In this paper we propose an initial model of this problem as a leader-follower Stackelberg game. We then formulate an LP relaxation of this problem and present initial experimental results using real-world ridership data from the Los Angeles Metro Rail system.