1,775 research outputs found
Stepwise Model Reconstruction of Robotic Manipulator Based on Data-Driven Method
Research on dynamics of robotic manipulators provides promising support for
model-based control. In general, rigorous first-principles-based dynamics
modeling and accurate identification of mechanism parameters are critical to
achieving high precision in model-based control, while data-driven model
reconstruction provides alternative approaches of the above process. Taking the
level of activation of data as an indicator, this paper classifies the
collected robotic manipulator data by means of K-means clustering algorithm.
With the fundamental prior knowledge, we find the corresponding dynamical
properties behind the classified data separately. Afterwards, the sparse
identification of nonlinear dynamics (SINDy) method is used to reconstruct the
dynamics model of the robotic manipulator step by step according to the
activation level of the classified data. The simulation results show that the
proposed method not only reduces the complexity of the basis function library,
enabling the application of SINDy method to multi-degree-of-freedom robotic
manipulators, but also decreases the influence of data noise on the regression
results. Finally, the dynamic control based on the reconfigured model is
deployed on the experimental platform, and the experimental results prove the
effectiveness of the proposed method.Comment: 8 pages, 11 figure
Connectionist Temporal Modeling for Weakly Supervised Action Labeling
We propose a weakly-supervised framework for action labeling in video, where
only the order of occurring actions is required during training time. The key
challenge is that the per-frame alignments between the input (video) and label
(action) sequences are unknown during training. We address this by introducing
the Extended Connectionist Temporal Classification (ECTC) framework to
efficiently evaluate all possible alignments via dynamic programming and
explicitly enforce their consistency with frame-to-frame visual similarities.
This protects the model from distractions of visually inconsistent or
degenerated alignments without the need of temporal supervision. We further
extend our framework to the semi-supervised case when a few frames are sparsely
annotated in a video. With less than 1% of labeled frames per video, our method
is able to outperform existing semi-supervised approaches and achieve
comparable performance to that of fully supervised approaches.Comment: To appear in ECCV 201
An Adaptive Neuro-Fuzzy Inference System Based Approach to Real Estate Property Assessment
This paper describes a first effort to design and implement an adaptive neuro-fuzzy inference system based approach to estimate prices for residential properties. The data set consists of historic sales of homes in a market in Midwest USA and it contains parameters describing typical residential property features and the actual sale price. The study explores the use of fuzzy inference systems to assess real estate property values and the use of neural networks in creating and fine tuning the fuzzy rules used in the fuzzy inference system. The results are compared with those obtained using a traditional multiple regression model. The paper also describes possible future research in this area.
Locating and quantifying gas emission sources using remotely obtained concentration data
We describe a method for detecting, locating and quantifying sources of gas
emissions to the atmosphere using remotely obtained gas concentration data; the
method is applicable to gases of environmental concern. We demonstrate its
performance using methane data collected from aircraft. Atmospheric point
concentration measurements are modelled as the sum of a spatially and
temporally smooth atmospheric background concentration, augmented by
concentrations due to local sources. We model source emission rates with a
Gaussian mixture model and use a Markov random field to represent the
atmospheric background concentration component of the measurements. A Gaussian
plume atmospheric eddy dispersion model represents gas dispersion between
sources and measurement locations. Initial point estimates of background
concentrations and source emission rates are obtained using mixed L2-L1
optimisation over a discretised grid of potential source locations. Subsequent
reversible jump Markov chain Monte Carlo inference provides estimated values
and uncertainties for the number, emission rates and locations of sources
unconstrained by a grid. Source area, atmospheric background concentrations and
other model parameters are also estimated. We investigate the performance of
the approach first using a synthetic problem, then apply the method to real
data collected from an aircraft flying over: a 1600 km^2 area containing two
landfills, then a 225 km^2 area containing a gas flare stack
Computational Intelligence Techniques for Control and Optimization of Wastewater Treatment Plants
The development of novel, practice-oriented and reliable instrumentation and control strategies for
wastewater treatment plants in order to improve energy efficiency, while guaranteeing process stability and
maintenance of high cleaning capacity, has become a priority for WWTP operators due to increasing
treatment costs. To achieve these ambitious and even contradictory objectives, this thesis investigates a
combination of online measurement systems, computational intelligence and machine learning methods as
well as dynamic simulation models. Introducing the state-of-the-art in the fields of WWTP operation,
process monitoring and control, three novel computational intelligence enabled instrumentation, control
and automation (ICA) methods are developed and presented. Furthermore, their potential for practical
implementation is assessed. The methods are, on the one hand, the automated calibration of a simulation
model for the Rospe WWTP that provides a basis for the development and evaluation of the subsequent
methods, and on the other hand, the development of soft sensors for the WWTP inflow which estimate the
crucial process variables COD and NH4-N, and the estimation of WWTP operating states using Self-
Organising Maps (SOM) that are used to determine the optimal control parameters for each state. These
collectively, provide the basis for achieving comprehensive WWTP optimization. Results show that energy
consumption and cleaning capacity can be improved by more than 50%
Development of Real-time Optimal Control Strategy of Hybrid Transit Bus Based on Predicted Driving Pattern
The control strategy of a hybrid electric vehicle (HEV) has been an active research area in the past decades. The main goal of the optimal control strategy is to maximize the fuel economy and minimize exhaust emissions while also satisfying the expected vehicle performance. Dynamic programming (DP) is an algorithm capable of finding the global optimal solution of HEV operation. However, DP cannot be used as a real-time control approach as it requires pre-known driving information. The equivalent consumption minimization strategy (ECMS) is a real-time control approach, but it always results in local optima due to the non-convex cost function. In my research, a ECMS with DP combined model (ECMSwDP) was proposed, which was a compromise between optimality and real-time capability. In this approach, the optimal equivalent factor (lambda) for a real-time ECMS controller can be derived using ECMSwDP for a given driving condition. The optimal lambda obtained using ECMSwDP was further processed to derive the lambda map, which was a function of vehicle operation and driving information. Six lambda maps were generated corresponding to the developed representative driving patterns. At each distance segment of a drive cycle, the suitable lambda value is available from one of the six lambda maps based on the identified driving pattern and current vehicle operation.;An adaptive ECMS (A-ECMS) model with a driving pattern identification model is developed to achieve the real-time optimal control for a HEV. A-ECMS was capable of controlling the ratio of power provided by the ICE and battery of a hybrid vehicle by selecting the lambda based on the identified lambda map. The effect on fuel consumption of the control strategies developed using the rule-based controller, ECMSwDP, A-ECMS, and DP was simulated using the parallel hybrid bus model developed in this research. The control strategies developed using A-ECMS are able to significantly improve the fuel economy while maintaining the battery charge sustainability. The corrected fuel economy observed with A-ECMS with a penalty function and the average lambda of RDPs was 5.55%, 13.67%, and 19.19% gap to that observed with DP when operated over the Beijing cycle, WVU-CSI cycle, and the actual transit bus route, respectively. The corrected fuel economy observed with A-ECMS with lambda maps of the RDPs was 4.83%, 10.61%, and 14.33% gap to that observed with DP when operated on the Beijing cycle, WVU-CSI cycle, and actual transit bus route, respectively. The simulation results demonstrated that the proposed A-ECMS approaches have the capability to achieve real time suboptimal control of a HEV while maintaining the charge sustainability of the battery
Computational Investigations of Biomolecular Mechanisms in Genomic Replication, Repair and Transcription
High fidelity maintenance of the genome is imperative to ensuring stability and proliferation of cells. The genetic material (DNA) of a cell faces a constant barrage of metabolic and environmental assaults throughout the its lifetime, ultimately leading to DNA damage. Left unchecked, DNA damage can result in genomic instability, inviting a cascade of mutations that initiate cancer and other aging disorders. Thus, a large area of focus has been dedicated to understanding how DNA is damaged, repaired, expressed and replicated. At the heart of these processes lie complex macromolecular dynamics coupled with intricate protein-DNA interactions. Through advanced computational techniques it has become possible to probe these mechanisms at the atomic level, providing a physical basis to describe biomolecular phenomena. To this end, we have performed studies aimed at elucidating the dynamics and interactions intrinsic to the functionality of biomolecules critical to maintaining genomic integrity: modeling the DNA editing mechanism of DNA polymerase III, uncovering the DNA damage recognition/repair mechanism of thymine DNA glycosylase and linking genetic disease to the functional dynamics of the pre-initiation complex transcription machinery. Collectively, our results elucidate the dynamic interplay between proteins and DNA, further broadening our understanding of these complex processes involved with genomic maintenance
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