24,966 research outputs found
Military newspapers and the Habsburg officers' ideology after 1868
The Habsburg officer corps of the late nineteenth century played a significant role in sustaining the feudal anachronism of the Austro-Hungarian Empire. Despite its constant appeals to tradition, it was in fact a product of the struggles to reform the army. The tensions that resulted are evident in the military press of the reform period and left their mark on the officers’ ideology
A First Step Towards Automatically Building Network Representations
To fully harness Grids, users or middlewares must have some knowledge on the
topology of the platform interconnection network. As such knowledge is usually
not available, one must uses tools which automatically build a topological
network model through some measurements. In this article, we define a
methodology to assess the quality of these network model building tools, and we
apply this methodology to representatives of the main classes of model builders
and to two new algorithms. We show that none of the main existing techniques
build models that enable to accurately predict the running time of simple
application kernels for actual platforms. However some of the new algorithms we
propose give excellent results in a wide range of situations
Single-Sweep Methods for Free Energy Calculations
A simple, efficient, and accurate method is proposed to map multi-dimensional
free energy landscapes. The method combines the temperature-accelerated
molecular dynamics (TAMD) proposed in [Maragliano & Vanden-Eijnden, Chem. Phys.
Lett. 426, 168 (2006)] with a variational reconstruction method using
radial-basis functions for the representation of the free energy. TAMD is used
to rapidly sweep through the important regions of the free energy landscape and
compute the gradient of the free energy locally at points in these regions. The
variational method is then used to reconstruct the free energy globally from
the mean force at these points. The algorithmic aspects of the single-sweep
method are explained in detail, and the method is tested on simple examples,
compared to metadynamics, and finally used to compute the free energy of the
solvated alanine dipeptide in two and four dihedral angles
From Physical to Cyber: Escalating Protection for Personalized Auto Insurance
Nowadays, auto insurance companies set personalized insurance rate based on
data gathered directly from their customers' cars. In this paper, we show such
a personalized insurance mechanism -- wildly adopted by many auto insurance
companies -- is vulnerable to exploit. In particular, we demonstrate that an
adversary can leverage off-the-shelf hardware to manipulate the data to the
device that collects drivers' habits for insurance rate customization and
obtain a fraudulent insurance discount. In response to this type of attack, we
also propose a defense mechanism that escalates the protection for insurers'
data collection. The main idea of this mechanism is to augment the insurer's
data collection device with the ability to gather unforgeable data acquired
from the physical world, and then leverage these data to identify manipulated
data points. Our defense mechanism leveraged a statistical model built on
unmanipulated data and is robust to manipulation methods that are not foreseen
previously. We have implemented this defense mechanism as a proof-of-concept
prototype and tested its effectiveness in the real world. Our evaluation shows
that our defense mechanism exhibits a false positive rate of 0.032 and a false
negative rate of 0.013.Comment: Appeared in Sensys 201
A Multilevel Approach to Topology-Aware Collective Operations in Computational Grids
The efficient implementation of collective communiction operations has
received much attention. Initial efforts produced "optimal" trees based on
network communication models that assumed equal point-to-point latencies
between any two processes. This assumption is violated in most practical
settings, however, particularly in heterogeneous systems such as clusters of
SMPs and wide-area "computational Grids," with the result that collective
operations perform suboptimally. In response, more recent work has focused on
creating topology-aware trees for collective operations that minimize
communication across slower channels (e.g., a wide-area network). While these
efforts have significant communication benefits, they all limit their view of
the network to only two layers. We present a strategy based upon a multilayer
view of the network. By creating multilevel topology-aware trees we take
advantage of communication cost differences at every level in the network. We
used this strategy to implement topology-aware versions of several MPI
collective operations in MPICH-G2, the Globus Toolkit[tm]-enabled version of
the popular MPICH implementation of the MPI standard. Using information about
topology provided by MPICH-G2, we construct these multilevel topology-aware
trees automatically during execution. We present results demonstrating the
advantages of our multilevel approach by comparing it to the default
(topology-unaware) implementation provided by MPICH and a topology-aware
two-layer implementation.Comment: 16 pages, 8 figure
MPICH-G2: A Grid-Enabled Implementation of the Message Passing Interface
Application development for distributed computing "Grids" can benefit from
tools that variously hide or enable application-level management of critical
aspects of the heterogeneous environment. As part of an investigation of these
issues, we have developed MPICH-G2, a Grid-enabled implementation of the
Message Passing Interface (MPI) that allows a user to run MPI programs across
multiple computers, at the same or different sites, using the same commands
that would be used on a parallel computer. This library extends the Argonne
MPICH implementation of MPI to use services provided by the Globus Toolkit for
authentication, authorization, resource allocation, executable staging, and
I/O, as well as for process creation, monitoring, and control. Various
performance-critical operations, including startup and collective operations,
are configured to exploit network topology information. The library also
exploits MPI constructs for performance management; for example, the MPI
communicator construct is used for application-level discovery of, and
adaptation to, both network topology and network quality-of-service mechanisms.
We describe the MPICH-G2 design and implementation, present performance
results, and review application experiences, including record-setting
distributed simulations.Comment: 20 pages, 8 figure
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