Planning & Scheduling
Artificial Intelligence And Its Impact On Contingent Workforce Management
One of the most important undertakings an enterprise has to deal with is finding and hiring an amazing candidate. But the fierce competition for talent, lackluster recruiting and sourcing processes and uncoordinated evaluation criteria make it an arduous task. Astoundingly, 74% of employers claim they've hired the wrong person for a position. These hires come at a cost, with organizations losing an average of nearly $15,000 on every bad hire. It's enticing to tap into artificial intelligence to help with hiring, managing and optimizing contingent workers.
Heuristic Approaches for Goal Recognition in Incomplete Domain Models
Pereira, Ramon Fraga, Meneguzzi, Felipe
Recent approaches to goal recognition have progressively relaxed the assumptions about the amount and correctness of domain knowledge and available observations, yielding accurate and efficient algorithms. These approaches, however, assume completeness and correctness of the domain theory against which their algorithms match observations: this is too strong for most real-world domains. In this paper, we develop goal recognition techniques that are capable of recognizing goals using \textit{incomplete} (and possibly incorrect) domain theories. We show the efficiency and accuracy of our approaches empirically against a large dataset of goal and plan recognition problems with incomplete domains.
Roster Evaluation Based on Classifiers for the Nurse Rostering Problem
Vรกclavรญk, Roman, ล ลฏcha, Pลemysl, Hanzรกlek, Zdenฤk
The personnel scheduling problem is a well-known NP-hard combinatorial problem. Due to the complexity of this problem and the size of the real-world instances, it is not possible to use exact methods, and thus heuristics, meta-heuristics, or hyper-heuristics must be employed. The majority of heuristic approaches are based on iterative search, where the quality of intermediate solutions must be calculated. Unfortunately, this is computationally highly expensive because these problems have many constraints and some are very complex. In this study, we propose a machine learning technique as a tool to accelerate the evaluation phase in heuristic approaches. The solution is based on a simple classifier, which is able to determine whether the changed solution (more precisely, the changed part of the solution) is better than the original or not. This decision is made much faster than a standard cost-oriented evaluation process. However, the classification process cannot guarantee 100% correctness. Therefore, our approach, which is illustrated using a tabu search algorithm in this study, includes a filtering mechanism, where the classifier rejects the majority of the potentially bad solutions and the remaining solutions are then evaluated in a standard manner. We also show how the boosting algorithms can improve the quality of the final solution compared with a simple classifier. We verified our proposed approach and premises, based on standard and real-world benchmark instances, to demonstrate the significant speedup obtained with comparable solution quality.
BBC Radio 1 announces major schedule changes
BBC Radio 1 has announced a major overhaul of its line-up, with the weekend schedule now starting on Fridays. Nick Grimshaw, Clara Amfo and Greg James will go down to hosting four shows a week as a result. New Friday shows have been announced for Maya Jama and The Saturdays' Mollie King as part of the changes, and Scott Mills will now host the chart show. Dev and Alice Levine will present the breakfast show from Friday to Sunday. Ben Cooper, controller of BBC Radio 1, said: "The weekend will start here at Radio 1 on a Friday morning giving our young audience that feel-good factor a day early. "It's our job at Radio 1 to reinvent the way young people listen to the radio, to disrupt traditional thinking and to look for new ways in which to grow audiences." The new schedule comes into effect in June. It's unclear how the schedule changes might affect the daytime hosts' current salaries, but a BBC spokesman said all presenters on the station are paid fairly. This marks the first time in Radio 1's history that the daytime DJs will be on a four-day week, although Chris Evans once tried to take Fridays off when he was hosting the breakfast show. In the late 1990s, he famously asked if he could host the programme only from Monday to Thursday - a request which was denied by then-controller Matthew Bannister. Jama joined the station earlier this year as the presenter of Radio 1's Greatest Hits. King has been appearing as a guest presenter with Edmondson in recent weeks but will now officially be a permanent fixture on the station. The singer, who appeared on the most recent series of Strictly Come Dancing, said: "I've grown up listening to Radio 1 and I can't wait to be one of the team.
Validation of Hierarchical Plans via Parsing of Attribute Grammars
Bartak, Roman (Charles University) | Maillard, Adrien (Charles University) | Cardoso, Rafael C. ( Pontifรญcia Universidade Catรณlica do Rio Grande do Sul )
An important problem of automated planning is validating if a plan complies with the planning domain model. Such validation is straightforward for classical sequential planning but until recently there was no such validation approach for Hierarchical Task Networks (HTN) planning. In this paper we propose a novel technique for validating HTN plans that is based on representing the HTN model as an attribute grammar and using a special parsing algorithm to verify if the plan can be generated by the grammar.
Probabilistic Planning by Probabilistic Programming
Belle, Vaishak (University of Edinburgh, Alan Turing Institute)
Automated planning is a major topic of research in artificial intelligence, and enjoys a long and distinguished history. The classical paradigm assumes a distinguished initial state, comprised of a set of facts, and is defined over a set of actions which change that state in one way or another. Planning in many real-world settings, however, is much more involved: an agent's knowledge is almost never simply a set of facts that are true, and actions that the agent intends to execute never operate the way they are supposed to. Thus, probabilistic planning attempts to incorporate stochastic models directly into the planning process. In this article, we briefly report on probabilistic planning through the lens of probabilistic programming: a programming paradigm that aims to ease the specification of structured probability distributions. In particular, we provide an overview of the features of two systems, HYPE and ALLEGRO, which emphasise different strengths of probabilistic programming that are particularly useful for complex modelling issues raised in probabilistic planning. Among other things, with these systems, one can instantiate planning problems with growing and shrinking state spaces, discrete and continuous probability distributions, and non-unique prior distributions in a first-order setting.
Comparing Plan Recognition Algorithms through Standard Libraries
Mirsky, Reuth (Ben-Gurion University of the Negev) | Galun, Ran (Ben-Gurion University of the Negev) | Gal, Ya' (Ben-Gurion University of the Negev) | akov (Bar-Ilan University) | Kaminka, Gal
Plan recognition isย one of the fundamental problems of AI, applicable to many domains, from user interfaces to cyber security. We focus on a class of algorithms that use plan libraries as input to the recognition process. Despite the prevalence of these approaches, they lack a standard representation, and have not been compared to each other on common test bed. This paper directly addresses this gap by providing a standard plan library representation and evaluation criteria to consider. Our representation is comprehensive enough to describe a variety of known plan recognition problems, yet it can be easily applied to existing algorithms, which can be evaluated using our defined criteria. We demonstrate this technique on two known algorithms, SBR and PHATT. We provide meaningful insights both about the differences and abilities of the algorithms. We show that SBR is superior to PHATT both in terms of computation time and space, but at the expense of functionality and compact representation. We also show that depth is the single feature of a plan library that increases the complexity of the recognition, regardless of the algorithm used.
Plan and Goal Recognition as HTN Planning
Hรถller, Daniel (Ulm University) | Bercher, Pascal (Ulm University) | Behnke, Gregor (Ulm University) | Biundo, Susanne (Ulm University)
Plan- and Goal Recognition (PGR) is the task of inferring the goals and plans of an agent based on its actions. A few years ago, an approach has been introduced that successfully exploits the performance of planning systems to solve it. That way, no specialized solvers are needed and PGR benefits from present and future research in planning. The approach uses classical planning systems and needs to plan (at least) once for every possible goal. However, models in PGR are often structured in a hierarchical way, similar to Hierarchical Task Networks (HTNs). These models are strictly more expressive than those in classical planning and can describe partially ordered sets of tasks or multiple goals with interleaving plans. We present the approach PGR as HTN Planning that enables the recognition of complex agent behavior by using unmodified, off-the-shelf HTN planners. Planning is thereby needed only once, regardless of how many possible goals there are. Our evaluation shows that current planning systems are able to handle large models with thousands of possible goals and that the approach results in high recognition rates.
Universal Planning Networks
Srinivas, Aravind, Jabri, Allan, Abbeel, Pieter, Levine, Sergey, Finn, Chelsea
A key challenge in complex visuomotor control is learning abstract representations that are effective for specifying goals, planning, and generalization. To this end, we introduce universal planning networks (UPN). UPNs embed differentiable planning within a goal-directed policy. This planning computation unrolls a forward model in a latent space and infers an optimal action plan through gradient descent trajectory optimization. The plan-by-gradient-descent process and its underlying representations are learned end-to-end to directly optimize a supervised imitation learning objective. We find that the representations learned are not only effective for goal-directed visual imitation via gradient-based trajectory optimization, but can also provide a metric for specifying goals using images. The learned representations can be leveraged to specify distance-based rewards to reach new target states for model-free reinforcement learning, resulting in substantially more effective learning when solving new tasks described via image-based goals. We were able to achieve successful transfer of visuomotor planning strategies across robots with significantly different morphologies and actuation capabilities.
AAAI News
Recently, AAAI coordinated and The Thirty-Third AAAI Conference on Artificial Intelligence (AAAI-19) cosigned a statement with CRA, and the Thirty-First Conference on Innovative Applications of Artificial expressing concern about the proposed Intelligence (IAAI-19), will be held in Honolulu, Hawaii, USA, January tax bill and its ramifications for graduate 27 - February 1, 2019. The technical conference will continue its student stipends. Other organizational 3.5-day schedule, preceded by the workshop and tutorial programs.