35,026 research outputs found
Initial State Stabilities and Inverse Engineering in Conflict Resolution
Two original contributions are made which extend the Graph Model for Conflict Resolution: one is a new family of solution concepts, while the other is a novel methodological approach. In addition to theoretical contributions, applications to complex energy problems are demonstrated; in particular, the consideration of the ongoing Trans Mountain Expansion Project is
the first of its kind.
The family of solution concepts, called initial state stabilities, is designed to complement existing solution concepts within the Graph Model framework by modelling both risk-averse and risk-seeking decision-makers. The comparison which underpins these concepts examines the consequences of moving from a given starting state to those of remaining in that state. The
types of individuals modelled by these stability concepts represent a new class of decision-makers which, up until now, had not been considered in the Graph Model paradigm.
The innovative methodology presented is designed to "inverse engineer" decision-makers’ preferences based on their observable behaviour. The algorithms underlying the inverse engineering methodology are based on the most commonly used stability concepts in the Graph Model for Conflict Resolution and function by reducing the set of possible preference
rankings for each decision-maker. The reduction is based on observable moves and counter-moves made by decision-makers. This procedure assists stakeholders in optimizing their own decision-making process based on information gathered about their opponents and can also be used to improve the modelling of strategic interactions.
In addition to providing decision-makers and analysts with up-to-date preference information about opponents, the methodology is also equipped with an ADVICE function which enriches the decision-making process by providing important information regarding potential moves. Decision-makers who use the methods introduced in this thesis are provided with
the expected value of each of their possible moves, with the probability of the opponent’s next response, and with the opponent reachable states. This insightful data helps establish an accurate picture of the conflict situation and in so doing, aids stakeholders in making strategic decisions. The applicability of this methodology is demonstrated through the study of the
conflict surrounding the Trans Mountain Expansion Project in British Columbia, Canada
Angular Upsampling in Infant Diffusion MRI Using Neighborhood Matching in x-q Space
Diffusion MRI requires sufficient coverage of the diffusion wavevector space,
also known as the q-space, to adequately capture the pattern of water diffusion
in various directions and scales. As a result, the acquisition time can be
prohibitive for individuals who are unable to stay still in the scanner for an
extensive period of time, such as infants. To address this problem, in this
paper we harness non-local self-similar information in the x-q space of
diffusion MRI data for q-space upsampling. Specifically, we first perform
neighborhood matching to establish the relationships of signals in x-q space.
The signal relationships are then used to regularize an ill-posed inverse
problem related to the estimation of high angular resolution diffusion MRI data
from its low-resolution counterpart. Our framework allows information from
curved white matter structures to be used for effective regularization of the
otherwise ill-posed problem. Extensive evaluations using synthetic and infant
diffusion MRI data demonstrate the effectiveness of our method. Compared with
the widely adopted interpolation methods using spherical radial basis functions
and spherical harmonics, our method is able to produce high angular resolution
diffusion MRI data with greater quality, both qualitatively and quantitatively.Comment: 15 pages, 12 figure
Computational intelligence approaches to robotics, automation, and control [Volume guest editors]
No abstract available
Driving with Style: Inverse Reinforcement Learning in General-Purpose Planning for Automated Driving
Behavior and motion planning play an important role in automated driving.
Traditionally, behavior planners instruct local motion planners with predefined
behaviors. Due to the high scene complexity in urban environments,
unpredictable situations may occur in which behavior planners fail to match
predefined behavior templates. Recently, general-purpose planners have been
introduced, combining behavior and local motion planning. These general-purpose
planners allow behavior-aware motion planning given a single reward function.
However, two challenges arise: First, this function has to map a complex
feature space into rewards. Second, the reward function has to be manually
tuned by an expert. Manually tuning this reward function becomes a tedious
task. In this paper, we propose an approach that relies on human driving
demonstrations to automatically tune reward functions. This study offers
important insights into the driving style optimization of general-purpose
planners with maximum entropy inverse reinforcement learning. We evaluate our
approach based on the expected value difference between learned and
demonstrated policies. Furthermore, we compare the similarity of human driven
trajectories with optimal policies of our planner under learned and
expert-tuned reward functions. Our experiments show that we are able to learn
reward functions exceeding the level of manual expert tuning without prior
domain knowledge.Comment: Appeared at IROS 2019. Accepted version. Added/updated footnote,
minor correction in preliminarie
Detecting Functional Requirements Inconsistencies within Multi-teams Projects Framed into a Model-based Web Methodology
One of the most essential processes within the software project life cycle is the REP (Requirements
Engineering Process) because it allows specifying the software product requirements. This specification
should be as consistent as possible because it allows estimating in a suitable manner the effort required to
obtain the final product. REP is complex in itself, but this complexity is greatly increased in big, distributed
and heterogeneous projects with multiple analyst teams and high integration between functional modules.
This paper presents an approach for the systematic conciliation of functional requirements in big projects
dealing with a web model-based approach and how this approach may be implemented in the context of the
NDT (Navigational Development Techniques): a web methodology. This paper also describes the empirical
evaluation in the CALIPSOneo project by analyzing the improvements obtained with our approach.Ministerio de EconomĂa y Competitividad TIN2013-46928-C3-3-RMinisterio de EconomĂa y Competitividad TIN2015-71938-RED
Automating Fine Concurrency Control in Object-Oriented Databases
Several propositions were done to provide adapted concurrency control to
object-oriented databases. However, most of these proposals miss the fact that
considering solely read and write access modes on instances may lead to less
parallelism than in relational databases! This paper cope with that issue, and
advantages are numerous: (1) commutativity of methods is determined a priori
and automatically by the compiler, without measurable overhead, (2) run-time
checking of commutativity is as efficient as for compatibility, (3) inverse
operations need not be specified for recovery, (4) this scheme does not
preclude more sophisticated approaches, and, last but not least, (5) relational
and object-oriented concurrency control schemes with read and write access
modes are subsumed under this proposition
Data Assimilation for a Geological Process Model Using the Ensemble Kalman Filter
We consider the problem of conditioning a geological process-based computer
simulation, which produces basin models by simulating transport and deposition
of sediments, to data. Emphasising uncertainty quantification, we frame this as
a Bayesian inverse problem, and propose to characterize the posterior
probability distribution of the geological quantities of interest by using a
variant of the ensemble Kalman filter, an estimation method which linearly and
sequentially conditions realisations of the system state to data.
A test case involving synthetic data is used to assess the performance of the
proposed estimation method, and to compare it with similar approaches. We
further apply the method to a more realistic test case, involving real well
data from the Colville foreland basin, North Slope, Alaska.Comment: 34 pages, 10 figures, 4 table
Symmetry-breaking Answer Set Solving
In the context of Answer Set Programming, this paper investigates
symmetry-breaking to eliminate symmetric parts of the search space and,
thereby, simplify the solution process. We propose a reduction of disjunctive
logic programs to a coloured digraph such that permutational symmetries can be
constructed from graph automorphisms. Symmetries are then broken by introducing
symmetry-breaking constraints. For this purpose, we formulate a preprocessor
that integrates a graph automorphism system. Experiments demonstrate its
computational impact.Comment: Proceedings of ICLP'10 Workshop on Answer Set Programming and Other
Computing Paradig
- …