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A contraction based stabilization problem of systems with approximate strict feedback form is considered here. A high gain feedback is used to force the system into singularly perturbed form. Contraction theory based recursive controller design and singular perturbation analysis is used to design a stabilizing controller for the whole system. It is shown that, explicit error bounds between trajectories...
This paper presents a subject centric group feature for person re-identification. Our approach is inspired by the observation that people often tend to walk alongside others or in a group. We argue that co-travelers' information, including geometry and visual cues, can reduce the re-identification ambiguity and lead to better accuracy, compared to approaches that rely only on visual cues. We introduce...
Leader identification is a crucial task in social analysis, crowd management and emergency planning. In this paper, we investigate a computational model for the individuation of leaders in crowded scenes. We deal with the lack of a formal definition of leadership by learning, in a supervised fashion, a metric space based exclusively on people spatiotemporal information. Based on Tarde's work on crowd...
This article deals with the evaluation of the effect of the small arms cartridge lubrication on the operation cycle of the automatic and the semi-automatic weapon. The course of the weapon's operation cycle has been measured using the digital high speed camera, utilizing the single-camera digital photogrammetry method.
We investigate a new method for the acquisition of bandlimited functions, which we call mobile sampling. A field is sampled by a mobile sensor that moves along a continuous path. In this context, it is possible to increase the spatial sampling rate along the sensor's path with marginal additional cost. Hence we assume that the sensors acquire the field values on its path at an arbitrarily high resolution...
We present a randomized kinodynamic planner that solves rearrangement planning problems. We embed a physics model into the planner to allow reasoning about interaction with objects in the environment. By carefully selecting this model, we are able to reduce our state and action space, gaining tractability in the search. The result is a planner capable of generating trajectories for full arm manipulation...
In order to develop provably safe human-in-the-loop systems, accurate and precise models of human behavior must be developed. Driving is a good example of such a system because the driver has full control of the vehicle, and her likely actions are highly dependent on her mental state and the context of the current situation. This paper presents a testbed for collecting driver data that allows us to...
This paper discusses machine learning and data mining approaches to analyzing maritime vessel traffic based on the Automated Information System (AIS). We review recent efforts to apply machine learning techniques to AIS data and put them in the context of the challenges posed by the need for both algorithmic performance generalization and interpretability of the results in real-world maritime Situational...
This paper presents algorithms for optimal selection of needle grasp, for autonomous robotic execution of the minimally invasive surgical suturing task. In order to minimize the tissue trauma during the suturing motion, the best practices of needle path planning that are used by surgeons are applied for autonomous robotic surgical suturing tasks. Once an optimal needle trajectory in a well-defined...
This paper presents an algorithm for aerial vehicle trajectory generation based on the optimal Rapidly-exploring Random Tree (RRT*). The trajectory generation for the aerial vehicle is a complex path planning problem since the vehicle flies in a heterogeneous environment. The vehicle must also avoid some obstacles or inaccessible zones such as buildings, mountains and even radar detection zones depending...
Robust, scalable place recognition is a core competency for many robotic applications. However, when revisiting places over and over, many state-of-the-art approaches exhibit reduced performance in terms of computation and memory complexity and in terms of accuracy. For successful deployment of robots over long time scales, we must develop algorithms that get better with repeated visits to the same...
This paper proposes an environmental representation approach based on hybrid metric and topological maps as a key component for mobile robot navigation. Focus is made on an ego-centric pose graph structure by the use of Keyframes to capture the local properties of the scene. With the aim of reducing data redundancy, suppress sensor noise whilst maintaining a dense compact representation of the environment,...
What is it that makes movement around obstacles hard? The answer seems clear: obstacles contort the geometry of the workspace and make it difficult to leverage what we consider easy and intuitive straight-line Cartesian geometry. But is Cartesian motion actually easy? It's certainly well-understood and has numerous applications. But beneath the details of linear algebra and pseudoinverses, lies a...
This paper considers a problem of optimal model approximation in a behavioral framework. For the class of linear time-invariant ℓ2-systems, an angle criterion is introduced to define the distance measure between two systems in this class. Given a system of degree n, a characterization of all optimal approximants of degree n − 1 is given. The result is derived using the notion of canonical past-future...
Quantifying the similarity between two trajectories is a fundamental operation in analysis of spatio-temporal databases. While a number of distance functions exist, the recent shift in the dynamics of the trajectory generation procedure violates one of their core assumptions; a consistent and uniform sampling rate. In this paper, we formulate a robust distance function called Edit Distance with Projections...
A suboptimality theorem, i.e. an ε-maximum principle for generalized control systems is proven which also applies in cases if there is no optimal trajectory. We apply the result to obtain a suboptimality theorem for differential inclusion problems.
In recent years, wireless communication technologies and accurate positioning devices enable us to enjoy various types of location-based services. However, revealing users location information to potentially untrusted LBS providers is one of the most significant privacy threats in location-based services. The dummy-based privacy-preserving approach is a popular technology that can protect real trajectories...
Lack of a comprehensive model for physical collaboration tasks motivated many researchers to focus on a particular aspect of the collaboration. In this work, we introduce a metric that quantifies the cooperative quality of a collaborative task. Based on the proposed model of cooperation, we present a set of five metrics that capture different properties of such tasks. The results of an empirical study...
Traditionally, grasp and arm motion planning are considered as separate tasks. This paper presents an integrated approach that only requires the initial configuration of the robotic arm and the pose of the target object to simultaneously plan a good hand pose and arm trajectory to grasp the object. The planner exploits the concept of independent contact regions to look for the best possible grasp...
One the causes of dysfunction of a mechatronic system can be the evolution of the value of some of its parameters. It is possible to model the behavior which must be performed through the representation of the impulse differential inclusion model. Especially the viability sets are identified in relationship with the reliability properties. A visual analysis process can be then conducted and also quantitative...
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