17041924
Non-equispaced Fourier Transform Vs. Polynomial-Based Metal Artifact Reduction in Computed Tomography
We propose a method, which treats metal artifact reduction in CT by sinogram restoration as a problem of scattered data interpolation. Corrupted sinogram entries are discarded and replaced with artificially generated values. The presented interpolation algorithm is based on the 2D non-equispaced fast Fourier transform (NFFT). Results are compared to two common polynomial interpolation schemes.
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.
35750619
Restricted T-Universal Functions
We prove the existence of a function @f which is holomorphic exactly in the unit disk D and has universal translates with respect to a prescribed closed set [email protected][email protected]?D and satisfies @[email protected]?C^~(@?D\E). If Q is a subsequence of N"0 with upper density d(Q)=1 then the function @f can be constructed such that in [email protected] (z)[email protected]?n=0~a"nz^nwitha"[email protected]?Q.
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.
44711307
Estimation of class membership functions for grey-level based image fusion
In this paper we propose a new unsupervised method for estimating class membership functions from statistical data. It combines in an original way information derived from the histogram as well as prior knowledge of the requirements that the functions must satisfy and that cannot be derived from the histogram. The method has been tested successfully on MR brain images, and applications to image fusion are illustrated.
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.
8947989
Submission of content to a digital object repository using a configurable workflow system
The prototype of a workflow system for the submission of content to a digital object repository is here presented. It is based entirely on open-source standard components and features a service-oriented architecture. The front-end consists of Java Business Process Management (jBPM), Java Server Faces (JSF), and Java Server Pages (JSP). A Fedora Repository and a mySQL data base management system serve as a back-end. The communication between front-end and back-end uses a SOAP minimal binding stub. We describe the design principles and the construction of the prototype and discuss the possibilities and limitations of work ow creation by administrators. The code of the prototype is open-source and can be retrieved in the project escipub at this http URL