Optimum rendezvous guidance study Interim report

Minimum fuel rendezvous guidance of powered interceptor from parking orbit to target in coplanar circular orbi

Numerical Calculation of Bessel Functions

A new computational procedure is offered to provide simple, accurate and flexible methods for using modern computers to give numerical evaluations of the various Bessel functions. The Trapezoidal Rule, applied to suitable integral representations, may become the method of choice for evaluation of the many Special Functions of mathematical physics.Comment: 10 page

Realistic, Extensible DNS and mDNS Models for INET/OMNeT++

The domain name system (DNS) is one of the core services in today's network structures. In local and ad-hoc networks DNS is often enhanced or replaced by mDNS. As of yet, no simulation models for DNS and mDNS have been developed for INET/OMNeT++. We introduce DNS and mDNS simulation models for OMNeT++, which allow researchers to easily prototype and evaluate extensions for these protocols. In addition, we present models for our own experimental extensions, namely Stateless DNS and Privacy-Enhanced mDNS, that are based on the aforementioned models. Using our models we were able to further improve the efficiency of our protocol extensions.Comment: Published in: A. F\"orster, C. Minkenberg, G. R. Herrera, M. Kirsche (Eds.), Proc. of the 2nd OMNeT++ Community Summit, IBM Research - Zurich, Switzerland, September 3-4, 201

Fast Construction of the Fejér and Clenshaw-Curtis Quadrature Rules

We present an elegant algorithm for stably and quickly generating the weights of Fejér's quadrature rules and of the Clenshaw-Curtis rule. The weights for an arbitrary number of nodes are obtained as the discrete Fourier transform of an explicitly defined vector of rational or algebraic numbers. Since these rules have the capability of forming nested families, some of them have gained renewed interest in connection with quadrature over multi-dimensional region

Zertifizierung von Verbriefungstransaktionen durch die True Sale International (TSI)

Asset Backed Securities als Instrumente des Kreditrisikotransfers haben in den letzten Jahren ein enormes Marktwachstum erreichen können. Durch die im Rahmen der Subprime-Krise aufgeworfenen Verwerfungen auf den weltweiten Finanzmärkten wird deren Existenz in letzter Zeit aber eher kritisch hinterfragt. Viele der durchgeführten Transaktionen gelten als zu intransparent und risikobehaftet. Im Rahmen dieser Arbeit soll der Fragestellung nachgegangen werden, ob eine Zertifizierung von Verbriefungstransaktionen durch die True Sale International (TSI) geeignet ist, das Transparenzniveau des Verbriefungsmarkts zu erhöhen und dadurch einen positiven Beitrag zur Weiterentwicklung des Marktes zu leisten. Es werden alle Voraussetzungen, welche die TSI an eine Zertifizierung knüpft, eingehend analysiert. Ein Vergleich von zertifizierten mit nicht zertifizierten Transaktionen wird vorgenommen, um abschließend Möglichkeiten zur Weiterentwicklung der Zertifizierungsbedingungen vorzustellen.Asset Backed Securities have widely been accepted as instruments of Credit Risk Transfer. Their existence has been questioned in respect to the disavowal of worldwide financial markets due to the subprime crisis. Many transactions are rumoured to be intransparent and risky. This working paper examines whether a certification of true sale transaction by True Sale International (TSI) is able to raise the level of transparency of securitisation markets and thereby contributes to a positive market development. A detailed analysis of all certification requirements imposed by TSI is undertaken. Non certified transactions are compared with certified transactions in order to present possibilities for the improvement of certification criteria

Quaternions for regularizing Celestial Mechanics: the right way

Quaternions have been found to be the ideal tool for describing and developing the theory of spatial regularization in Celestial Mechanics. This article corroborates the above statement. Beginning with a summary of quaternion algebra, we will describe the regularization procedure and its consequences in an elegant way. Also, an alternative derivation of the theory of Kepler motion based on regularization will be given. Furthermore, we will consider the regularization of the spatial restricted three-body problem, i.e. the spatial generalization of the Birkhoff transformation. Finally, the perturbed Kepler motion will be described in terms of regularized variable

Quaternions and the perturbed Kepler problem

Quaternions, introduced by Hamilton (Philos. Mag. 25, 489-495, 1844) as a generalization of complex numbers, lead to a remarkably simple representation of the perturbed three-dimensional Kepler problem as a perturbed harmonic oscillator. The paper gives an overview of this technique, including an outlook to applications in perturbation theorie

Darkmold Archaeological Site Analysis: Three Dimensional Surface Modeling and Data Compilation

Archaeology is a spatial discipline, which is why using Geographic Information Systems (GIS) analysis is a powerful tool for archaeological applications. In the past, the use of GIS by archaeologists consisted of site location prediction, or related applications covering large areas. This project is concentrated on a single site in southwestern Colorado, known as the Darkmold Site. The purpose of this project is to amass data collected from the site, convert it to digital format to be used in the ArcGIS software made by ESRI, and return it to the client in a form that can be updated and maintained through future field seasons. Converting the data is no small task because in the field data is recorded on paper forms and collected using a Total Station. However, neither of these collection methods imports easily into the software. The data assemblage of this project involves the creation of a personal geodatabase to store the data, and manipulation and conversion of files into accepted formats. The three dimensional surface models are the results of interpolating the ground surface elevation of the site after each year of excavation. Briefly, the methodology for creating the surface models involves creating Triangulated Irregular Network (TIN) surfaces from point and line data, and converting the TIN to a raster surface. This project also includes a discussion on relating data of spatial tables to standalone tables, which is basic to GIS, to allow for simultaneous querying of the data in the GIS. The importance of this project to the use of GIS in archaeology is not only in the methods, but in the realization of what is required to build a successful GIS application. For GIS analysis to be successful at the site level, excavation methods must incorporate data collection for the goals of the GIS

The rhomboidal symmetric four-body problem

We consider the planar symmetric four-body problem with two equal masses m 1=m 3>0 at positions (±x 1(t),0) and two equal masses m 2=m 4>0 at positions (0, ±x 2(t)) at all times t, referred to as the rhomboidal symmetric four-body problem. Owing to the simplicity of the equations of motion this problem is well suited to study regularization of the binary collisions, periodic solutions, chaotic motion, as well as the four-body collision and escape manifolds. Furthermore, resonance phenomena between the two interacting rectilinear binaries play an important rol

Use of Quinolones for the Treatment of Osteomyelitis and Septic Arthritis

The low minimal inhibitory concentrations and minimal bactericidal concentrations of the quinolones for most pathogenic gram-negative and many gram-positive organisms, the ease of their administration, and their good oral absorption make them good candidates for the treatment of chronic bone infections. Data presently available suggest that the quinolones are effective in the treatment of experimental osteomyelitis due to Pseudomonas aeruginosa, osteomyelitis due to other gram-negative organisms, and (when combined with rifampin) in the treatment of gram-positive osteomyelitides. Quinolones have also been shown to be effective in the treatment of experimental septic arthritis. These results were confirmed by clinical studies. Quinolones have been effective in the treatment of patients with gram-negative bacterial bone infections and have been as effective as conventional antistaphylococcal therapy in the treatment of osteomyelitis due to Staphylococcus aureus. Finally, it should be kept in mind that as yet quinolones have not been released for use as therapy for childhood infection