1,926 research outputs found
A Real-Time Remote IDS Testbed for Connected Vehicles
Connected vehicles are becoming commonplace. A constant connection between
vehicles and a central server enables new features and services. This added
connectivity raises the likelihood of exposure to attackers and risks
unauthorized access. A possible countermeasure to this issue are intrusion
detection systems (IDS), which aim at detecting these intrusions during or
after their occurrence. The problem with IDS is the large variety of possible
approaches with no sensible option for comparing them. Our contribution to this
problem comprises the conceptualization and implementation of a testbed for an
automotive real-world scenario. That amounts to a server-side IDS detecting
intrusions into vehicles remotely. To verify the validity of our approach, we
evaluate the testbed from multiple perspectives, including its fitness for
purpose and the quality of the data it generates. Our evaluation shows that the
testbed makes the effective assessment of various IDS possible. It solves
multiple problems of existing approaches, including class imbalance.
Additionally, it enables reproducibility and generating data of varying
detection difficulties. This allows for comprehensive evaluation of real-time,
remote IDS.Comment: Peer-reviewed version accepted for publication in the proceedings of
the 34th ACM/SIGAPP Symposium On Applied Computing (SAC'19
Is Gastronomy A Relevant Factor for Sustainable Tourism? An Empirical Analysis of Spain Country Brand
Tourism has become a fundamental industry for the economic growth of many countries. Due to this, there is growing competitiveness among the different destinations to attract as many tourists as possible. As a result, disciplines such as marketing have developed tools to differentiate some destinations from others and concepts such as place branding and country brand have emerged. One of the key factors forming the country brand is gastronomy, as food tourism is one way to reduce
the growing problem of sustainability in tourism, as it impacts different aspects of the country’s environment. However, there is a great lack of scientific works that relate both variables. In this paper, we propose to establish that, in the case of Spain, tourists’ perception of Spanish gastronomy is a key element of its country brand. To do that, this study relies on the use of Partial Least Squares Structural Equations Modeling (PLS-SEM) using a 496 cases data set
A class of Hamilton-Jacobi equations on Banach-Finsler manifolds
The concept of subdifferentiability is studied in the context of
Finsler manifolds (modeled on a Banach space with a Lipschitz bump
function). A class of Hamilton-Jacobi equations defined on Finsler
manifolds is studied and several results related to the existence and
uniqueness of viscosity solutions are obtained.Comment: 24 page
Correcting symmetry imperfections in linear multipole traps
Multipole radio-frequency traps are central to collisional experiments in
cryogenic environments. They also offer possibilities to generate new type of
ion crystals topologies and in particular the potential to create infinite
1D/2D structures: ion rings and ion tubes. However, multipole traps have also
been shown to be very sensitive to geometrical misalignment of the trap rods,
leading to additional local trapping minima. The present work proposes a method
to correct non-ideal potentials, by modifying the applied radio-frequency
amplitudes for each trap rod. This approach is discussed for the octupole trap,
leading to the restitution of the ideal Mexican-Hat-like pseudo-potential,
expected in multipole traps. The goodness of the compensation method is
quantified in terms of the choice of the diagnosis area, the residual trapping
potential variations, the required adaptation of the applied radio-frequency
voltage amplitudes, and the impact on the trapped ion structures. Experimental
implementation for macroscopic multipole traps is also discussed, in order to
propose a diagnostic method with respect to the resolution and stability of the
trap drive. Using the proposed compensation technique, we discuss the
feasibility of generating a homogeneous ion ring crystal, which is a measure of
quality for the obtained potential well
Fast accumulation of ions in a dual trap
Transporting charged particles between different traps has become an
important feature in high-precision spectroscopy experiments of different
types. In many experiments in atomic and molecular physics, the optical probing
of the ions is not carried out at the same location as the creation or state
preparation. In our double linear radio-frequency trap, we have implemented a
fast protocol allowing to shuttle large ion clouds very efficiently between
traps, in times shorter than a millisecond. Moreover, our shuttling protocol is
a one-way process, allowing to add ions to an existing cloud without loss of
the already trapped sample. This feature makes accumulation possible, resulting
in the creation of large ion clouds. Experimental results show, that ion clouds
of large size are reached with laser-cooling, however, the described mechanism
does not rely on any cooling process
Parallel ion strings in linear multipole traps
Additional radio-frequency (rf) potentials applied to linear multipole traps
create extra field nodes in the radial plane which allow one to confine single
ions, or strings of ions, in totally rf field-free regions. The number of nodes
depends on the order of the applied multipole potentials and their relative
distance can be easily tuned by the amplitude variation of the applied
voltages. Simulations using molecular dynamics show that strings of ions can be
laser cooled down to the Doppler limit in all directions of space. Once cooled,
organized systems can be moved with very limited heating, even if the cooling
process is turned off
Defect generation and dynamics during quenching in finite size homogeneous ion chains
An equally spaced linear chain of ions provides a test-bed for studying the
defect formation in a finite size 1D system. In particular, defect formation
related to topological phase transition from a linear configuration to a
zig-zag one is of interest here. A semi-empirical expression provides an
excellent agreement to the numerical results. The non-adiabatic transition
between the chain and zig-zag topologies for a finite size system of 30 ions
shows clear distinction from non-uniformly distributed ion chain. Thus the
underlying Homogeneous Kibble-Zurek model can be tested in presently accessible
ion trap experiments. Furthermore, our study indicates collective defect
behaviour appearing through the correlation length measurements
ExplainIt! -- A declarative root-cause analysis engine for time series data (extended version)
We present ExplainIt!, a declarative, unsupervised root-cause analysis engine
that uses time series monitoring data from large complex systems such as data
centres. ExplainIt! empowers operators to succinctly specify a large number of
causal hypotheses to search for causes of interesting events. ExplainIt! then
ranks these hypotheses, reducing the number of causal dependencies from
hundreds of thousands to a handful for human understanding. We show how a
declarative language, such as SQL, can be effective in declaratively
enumerating hypotheses that probe the structure of an unknown probabilistic
graphical causal model of the underlying system. Our thesis is that databases
are in a unique position to enable users to rapidly explore the possible causal
mechanisms in data collected from diverse sources. We empirically demonstrate
how ExplainIt! had helped us resolve over 30 performance issues in a commercial
product since late 2014, of which we discuss a few cases in detail.Comment: SIGMOD Industry Track 201
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