Multiple CSLs for the body centered cubic lattice

Ordinary Coincidence Site Lattices (CSLs) are defined as the intersection of a lattice $\Gamma$ with a rotated copy $R\Gamma$ of itself. They are useful for classifying grain boundaries and have been studied extensively since the mid sixties. Recently the interests turned to so-called multiple CSLs, i.e. intersections of $n$ rotated copies of a given lattice $\Gamma$, in particular in connection with lattice quantizers. Here we consider multiple CSLs for the 3-dimensional body centered cubic lattice. We discuss the spectrum of coincidence indices and their multiplicity, in particular we show that the latter is a multiplicative function and give an explicit expression of it for some special cases.Comment: 4 pages, SSPCM (31 August - 7 September 2005, Myczkowce, Poland

Imaging Pulsed Laser Deposition oxide growth by in-situ Atomic Force Microscopy

To visualize the topography of thin oxide films during growth, thereby enabling to study its growth behavior quasi real-time, we have designed and integrated an atomic force microscope (AFM) in a pulsed laser deposition (PLD) vacuum setup. The AFM scanner and PLD target are integrated in a single support frame, combined with a fast sample transfer method, such that in-situ microscopy can be utilized after subsequent deposition pulses. The in-situ microscope can be operated from room temperature (RT) up to 700$^\circ$C and at (process) pressures ranging from the vacuum base pressure of 10$^{-6}$ mbar up to 1 mbar, typical PLD conditions for the growth of oxide films. The performance of this instrument is demonstrated by resolving unit cell height surface steps and surface topography under typical oxide PLD growth conditions.Comment: 8 pages, 8 figure

Determining the energetics of vicinal perovskite oxide surfaces

The energetics of vicinal SrTiO$_3$(001) and DyScO$_3$(110), prototypical perovskite vicinal surfaces, has been studied using topographic atomic force microscopy imaging. The kink formation and strain relaxation energies are extracted from a statistical analysis of the step meandering. Both perovskite surfaces have very similar kink formation energies and exhibit a similar triangular step undulation. Our experiments suggest that the energetics of perovskite oxide surfaces is mainly governed by the local oxygen coordination.Comment: 16 pages, 4 figure

Cyber System Assurance through Improved Network Anomaly Modeling and Detection

NPS NRP Project PosterCyber System Assurance through Improved Network Anomaly Modeling and DetectionN8 - Integration of Capabilities & ResourcesThis research is supported by funding from the Naval Postgraduate School, Naval Research Program (PE 0605853N/2098). https://nps.edu/nrpChief of Naval Operations (CNO)Approved for public release. Distribution is unlimited.

Shipboard AIS Anti-Spoofing and Sanitization (SAASS)

NPS NRP Executive SummaryThis project refined, implemented, and tested exploratory prior work intended to secure a digital message ingestion path, the Automatic Identification System (AIS), common to all large commercial vessels and most other medium and large ships. Leveraging sanitization concepts and preliminary algorithms of Vasquez’s (2021) thesis, we developed new Python-based algorithms to randomly change least-significant bits in most sender-definable fields of Type 1, 2, and 3 AIS messages, attempting to maximize digital security while restraining the degradation of critical values used to forecast and avoid collisions at sea. We instantiated these algorithms into an AIS message handling program on a Raspberry Pi Model 4 B and then evaluated the performance of this AIS message manipulator when handling a variety of AIS message types intended to simulate real-world vessel traffic scenarios and conditions. In its current state, the manipulator substantially reduces the volume and types of AIS messages accepted into the integrated bridge and navigation system (IBNS), archives all received messages, and operates throughout the entire testing period with no operator intervention. As implemented on a Pi 4 using the Python programming language, our algorithm is unable to filter and modify AIS messages arriving at the manipulator at the maximum AIS protocol receipt rate of one message every 0.01333 s.Approved for public release. Distribution is unlimited.This research is supported by funding from the Naval Postgraduate School, Naval Research Program (PE 0605853N/2098). https://nps.edu/nrpChief of Naval Operations (CNO)N2/N6 - Information Warfar

Exponential distribution of long heart beat intervals during atrial fibrillation and their relevance for white noise behaviour in power spectrum

The statistical properties of heart beat intervals of 130 long-term surface electrocardiogram recordings during atrial fibrillation (AF) are investigated. We find that the distribution of interbeat intervals exhibits a characteristic exponential tail, which is absent during sinus rhythm, as tested in a corresponding control study with 72 healthy persons. The rate of the exponential decay lies in the range 3-12 Hz and shows diurnal variations. It equals, up to statistical uncertainties, the level of the previously uncovered white noise part in the power spectrum, which is also characteristic for AF. The overall statistical features can be described by decomposing the intervals into two statistically independent times, where the first one is associated with a correlated process with 1/f noise characteristics, while the second one belongs to an uncorrelated process and is responsible for the exponential tail. It is suggested to use the rate of the exponential decay as a further parameter for a better classification of AF and for the medical diagnosis. The relevance of the findings with respect to a general understanding of AF is pointed out

Cyber System Assurance through Improved Network Anomaly Modeling and Detection

NPS NRP Technical ReportCyber System Assurance through Improved Network Anomaly Modeling and DetectionN8 - Integration of Capabilities & ResourcesThis research is supported by funding from the Naval Postgraduate School, Naval Research Program (PE 0605853N/2098). https://nps.edu/nrpChief of Naval Operations (CNO)Approved for public release. Distribution is unlimited.

Cyber System Assurance through Improved Network Anomaly Modeling and Detection

NPS NRP Executive SummaryCyber System Assurance through Improved Network Anomaly Modeling and DetectionN8 - Integration of Capabilities & ResourcesThis research is supported by funding from the Naval Postgraduate School, Naval Research Program (PE 0605853N/2098). https://nps.edu/nrpChief of Naval Operations (CNO)Approved for public release. Distribution is unlimited.

A Precision Measurement of pp Elastic Scattering Cross Sections at Intermediate Energies

We have measured differential cross sections for \pp elastic scattering with internal fiber targets in the recirculating beam of the proton synchrotron COSY. Measurements were made continuously during acceleration for projectile kinetic energies between 0.23 and 2.59 GeV in the angular range $30 \leq \theta_{c.m.} \leq 90$ deg. Details of the apparatus and the data analysis are given and the resulting excitation functions and angular distributions presented. The precision of each data point is typically better than 4%, and a relative normalization uncertainty of only 2.5% within an excitation function has been reached. The impact on phase shift analysis as well as upper bounds on possible resonant contributions in lower partial waves are discussed.Comment: 23 pages 29 figure

Loss of CCR7 Expression on CD56brightCD56^{bright} NK Cells Is Associated with a CD56dimCD16+CD56^{dim}CD16^{+} NK Cell-Like Phenotype and Correlates with HIV Viral Load

NK cells are pivotal sentinels of the innate immune system and distinct subpopulations in peripheral blood have been described. A number of studies addressed HIV-induced alterations of NK cell phenotype and functionality mainly focusing on $CD56^{dim}CD16^{+}$ and $CD56^{-} CD16^{+}$ NK cells. However, the impact of HIV-infection on $CD56^{bright}$ NK cells is less well understood. Here we report a rise of $CD56^{bright}$ NK cells in HIV-infected individuals, which lack CCR7-expression and strongly correlate with HIV viral load. $CCR7^{−} CD56^{bright}$ NK cells were characterized by increased cytolytic potential, higher activation states and a more differentiated phenotype. These cells thus acquired a number of features of $CD56^{dim}CD16^{+}$ NK cells. Furthermore, $CD56^{bright}$ NK cells from HIV patients exhibited higher degranulation levels compared to uninfected individuals. Thus, chronic HIV-infection is associated with a phenotypic and functional shift of $CD56^{bright}$ NK cells, which provides a novel aspect of HIV-associated pathogenesis within the NK cell compartment