15823454
Improved Monte Carlo localization of autonomous robots through simultaneous estimation of motion model parameters
In recent years, there has been an increasing interest in autonomous navigation for lightweight flying robots. With regard to self-localization flying robots have several limitations compared to ground vehicles. Due to their limited payload flying vehicles possess only limited computational resources and are restricted to a few and lightweight sensors. Additionally the kinematics of flying robots is rather complex, which requires sophisticated motion models that are typically hard to calibrate. However, as the sensors provide only a limited amount of information, the motion models need to be highly accurate to reduce the potential increase of uncertainty caused by the movements of the vehicle. In this paper, we present a novel approach to simultaneous localization and estimation of motion model parameters and their adaptation in the context of a particle filter. To deal with sudden changes of parameters, our approach utilizes random sampling augmented by additional damping to avoid oscillations caused by the delayed detection of the changes. As we demonstrate in experiments with a real blimp, our method can deal with very sparse and imprecise sensor information and outperforms a standard Monte Carlo localization approach.
8412425
A probabilistic sonar sensor model for robust localization of a small-size blimp in indoor environments using a particle filter
In recent years, autonomous miniature airships have gained increased interest in the robotics community. This is due to their ability to move safely and hover for extended periods of time. The major constraints of miniature airships come from their limited payload which introduces substantial constraints on their perceptional capabilities. In this paper, we consider the problem of localizing a miniature blimp with lightweight ultrasound sensors. Since the opening angle of the sound cone emitted by a sonar sensor depends on the diameter of the membrane, small-size sonar devices introduce the problem of high uncertainty about which object has been perceived. We present a novel sensor model for ultrasound sensors with large opening angles that allows an autonomous blimp to robustly localize itself in a known environment using Monte Carlo localization. As we demonstrate in experiments with a real blimp, our novel sensor model outperforms a popular sensor model that has in the past been shown to work reliably on wheeled platforms.
9329311
Intersection Line Length Normalization in CT Projection Data
We present a method to improve the quality of common sinogram restoration algorithms, which are used for metal-artifact reduction in X-ray CT. The presented approach is based on the idea that the intersection length of all beams through the object of interest can approximately be calculated from a preliminary reconstruction of the object. Incorporating this information to the reconstruction allows significant reduction of streak artifacts. Additionally, it is shown that the information about intersection length may also be used to improve the detection of metal shadows within the sinogram.
205705738
A lacunary version of Mergelian's approximation theorem
Let K be a compact plane set having connected complement. Then Mergelian's theorem states that the linear span of the monomials z^n, i.e. the polynomials, are dense in the Banach space A(K) of all functions continuous on K and holomorphic in the interior of K endowed with the sup-norm. We consider the question under which conditions the linear span of z^n, with n running through a sequence of nonnegative integers having upper density one, is dense in A(K) or appropriate subspaces.
14036610
Service-oriented support of cooperative workflows considerations for urban planning processes
Web-based information sources have evolved to an essential element in our daily and professional life. To process this faster and faster growing amount of information, web portals provide personalized access to specific information and communication services. In this paper, an example from urban planning is given. In this workflow, different actors are interacting in an ad-hoc manner. Therefore, a Portal Architecture has been built up, which provides the relevant information. This paper proposes a Service Orientated Architecture to provide access to business processes, software applications and hardware resources in a workflow oriented way.
45661231
Customizing Enterprise Software as a Service Applications: Back-End Extension in a Multi-tenancy Environment
Since the emerge of Salesforce.com, more and more business applications tend to move towards Software as a Service. In order to target Small and Medium-sized Enterprises, platform providers need to lower their operational costs and establish an ecosystem of partners, customizing their generic solution, to push their products into spot markets. This paper categorizes customization options, identifies cornerstones of a customizable, multi-tenancy aware infrastructure, proposes a framework that encapsulates multi-tenancy, and introduces a technique for partner back-end customizations with regard to a given real-world scenario.
3419898
Gain in Transparency versus Investment in the EPC Network - Analysis and Results of a Discrete Event Simulation Based on a Case Study in the Fashion Industry
The diffusion rate of Radio Frequency Identification (RFID) technology in supply chains is lower than expected. The main reason is the doubtful Return On Investment (ROI) mainly due to high tag prices. In this contribution, we leverage a prototypical RFID implementation in the fashion industry, extend this prototype by a discrete event simulation, and discuss the impact of an Electronic Product Code (EPC)-enabled supply chain concerning higher visibility. Thereby, we illustrate the benefit of the EPC network for Supply Chain Event Management (SCEM). Future researchers are provided with the simulation data which is available online and can be investigated.