Optimized signal deduction procedure for the MIEZE neutron spectroscopy technique

We report a method to determine the phase and amplitude of sinusoidally modulated event rates, binned into 4 bins per oscillation. The presented algorithm relies on a reconstruction of the unknown parameters. It omits a calculation intensive fitting procedure and avoids contrast reduction due to averaging effects. It allows the current data acquisition bottleneck to be relaxed by a factor of 4. Here, we explain the approach in detail and compare it to the established fitting procedures of time series having 4 and 16 time bins per oscillation. In addition we present the empirical estimates of the errors of the three methods and compare them to each other. We show that the reconstruction is unbiased, asymptotic, and efficient for estimating the phase. Reconstructing the contrast, which corresponds to the amplitude of the modulation, is roughly 10% less efficient than fitting 16 time binned oscillations. Finally, we give analytical equations to estimate the error for phase and contrast as a function of their initial values and counting statistics.Comment: 14 pages, 5 figures, submitted to IOP Measurement Science and Technolog

Mobile Phones as Secure Gateways for Message-Based Ubiquitous Communication (Revised)

For ubiquitous communication self-organising ad-hoc networks become more and more important. We consider mobile phones as appropriate secure gateways to provide access to the Internet for external machines with low communication needs. A message-based approach is best in such a scenario with moving mobile phones and machines. In this paper we propose a security model for access control to the communication infrastructure, which is also message oriented. To meet the requirements of ubiquitously communicating machines, all algorithms on the sender\u27s side are based on symmetric cryptography resulting in low computation requirements. Our sophisticated symmetric key infrastructure for access control is based on unique combinations of keys and is completed with an effective key management. This results in a carrier grade security level although many parties share the same keys. Adopting the Subscriber Identity Module as a secure storage and computing module achieves the trustworthiness of the mobile phone. This makes it possible to use the mobile phone not only as a user terminal but also as a trusted infrastructure component of the mobile network. This document is an update of earlier work [BWS07] presented at the Workshop in Information Security Theory and Practices 2007 in Crete, Greece

Analysis of a Large Sample of Neutrino-Induced Muons with the ArgoNeuT Detector

ArgoNeuT, or Argon Neutrino Test, is a 170 liter liquid argon time projection chamber designed to collect neutrino interactions from the NuMI beam at Fermi National Accelerator Laboratory. ArgoNeuT operated in the NuMI low-energy beam line directly upstream of the MINOS Near Detector from September 2009 to February 2010, during which thousands of neutrino and antineutrino events were collected. The MINOS Near Detector was used to measure muons downstream of ArgoNeuT. Though ArgoNeuT is primarily an R&D project, the data collected provide a unique opportunity to measure neutrino cross sections in the 0.1-10 GeV energy range. Fully reconstructing the muon from these interactions is imperative for these measurements. This paper focuses on the complete kinematic reconstruction of neutrino-induced through-going muons tracks. Analysis of this high statistics sample of minimum ionizing tracks demonstrates the reliability of the geometric and calorimetric reconstruction in the ArgoNeuT detector

Chemical injuries of the oesophagus: aetiopathological issues in Nigeria

<p>Abstract</p> <p>Background</p> <p>Chemical injuries of the oesophagus occur worldwide. There is paucity of information on aetiopathological profile of chemical injuries of the oesophagus in Nigeria.</p> <p>Aim</p> <p>The aim of the study was to determine the aetiopathological pattern of chemical injuries of the oesophagus in Nigeria.</p> <p>Materials and methods</p> <p>This is a multi-centre hospital based study in Lagos metropolis spanning a period of 10 years.</p> <p>The patients' bio data, substances ingested, sources of corrosives, reasons for ingesting corrosives and patients' mental state were recorded.</p> <p>Results</p> <p>In all, there were 78 patients (61 Males, 17 Females). The offending agents were acids in 55.1% of cases and it was accidental ingestion in 62 patients. The highest incidence of 57.6% was found in the middle 1/3 of the oesophagus.</p> <p>Conclusion</p> <p>Accidental ingestion of acids is the commonest cause of oesophageal injuries in Nigeria. The incidence of severe strictures necessitating oesophageal substitution could be reduced if early management of corrosive oesophagitis improves in Nigeria.</p