3,385 research outputs found
Wirelessly accessing instruments with standard GPIB/WLAN interfaces
The final objective of the project is to provide a Smartphone/GPIB interface. A small hardware and an Android application will allow the user to connect easily on a GPIB bus to send and receive data and commands. The device developed must offer a new and easier way to connect and get data from the instruments. The circuit must provide a transparent connection between the smartphone and the GPIB bus
Pulse-efficient quantum machine learning
Quantum machine learning algorithms based on parameterized quantum circuits
are promising candidates for near-term quantum advantage. Although these
algorithms are compatible with the current generation of quantum processors,
device noise limits their performance, for example by inducing an exponential
flattening of loss landscapes. Error suppression schemes such as dynamical
decoupling and Pauli twirling alleviate this issue by reducing noise at the
hardware level. A recent addition to this toolbox of techniques is
pulse-efficient transpilation, which reduces circuit schedule duration by
exploiting hardware-native cross-resonance interaction. In this work, we
investigate the impact of pulse-efficient circuits on near-term algorithms for
quantum machine learning. We report results for two standard experiments:
binary classification on a synthetic dataset with quantum neural networks and
handwritten digit recognition with quantum kernel estimation. In both cases, we
find that pulse-efficient transpilation vastly reduces average circuit
durations and, as a result, significantly improves classification accuracy. We
conclude by applying pulse-efficient transpilation to the Hamiltonian
Variational Ansatz and show that it delays the onset of noise-induced barren
plateaus.Comment: 8 pages, 6 figure
Microbioma Pulmonar: um caminho para medicina de precisão
O corpo humano é um ecossistema habitado por uma vasta gama de microrganismos, destacando-se entre eles vÃrus, bactérias e fungos, cujo conjunto é conhecido como "microbioma" ou "microbiota". A composição da microbiota humana é altamente individualizada e desempenha um papel fundamental no desenvolvimento e funcionamento de diversas partes do organismo
A Verified Information-Flow Architecture
SAFE is a clean-slate design for a highly secure computer system, with
pervasive mechanisms for tracking and limiting information flows. At the lowest
level, the SAFE hardware supports fine-grained programmable tags, with
efficient and flexible propagation and combination of tags as instructions are
executed. The operating system virtualizes these generic facilities to present
an information-flow abstract machine that allows user programs to label
sensitive data with rich confidentiality policies. We present a formal,
machine-checked model of the key hardware and software mechanisms used to
dynamically control information flow in SAFE and an end-to-end proof of
noninterference for this model.
We use a refinement proof methodology to propagate the noninterference
property of the abstract machine down to the concrete machine level. We use an
intermediate layer in the refinement chain that factors out the details of the
information-flow control policy and devise a code generator for compiling such
information-flow policies into low-level monitor code. Finally, we verify the
correctness of this generator using a dedicated Hoare logic that abstracts from
low-level machine instructions into a reusable set of verified structured code
generators
The cold-atom elevator: From edge-state injection to the preparation of fractional Chern insulators
Optical box traps for cold atoms offer new possibilities for quantum-gas
experiments. Building on their exquisite spatial and temporal control, we
propose to engineer system-reservoir configurations using box traps, in view of
preparing and manipulating topological atomic states in optical lattices.
First, we consider the injection of particles from the reservoir to the system:
this scenario is shown to be particularly well suited to activate
energy-selective chiral edge currents, but also, to prepare fractional Chern
insulating ground states. Then, we devise a practical evaporative-cooling
scheme to effectively cool down atomic gases into topological ground states.
Our open-system approach to optical-lattice settings provides a new path for
the investigation of ultracold quantum matter, including strongly-correlated
and topological phases.Comment: 15 pages, 11 figures including Supplementary materia
Preserving Both Privacy and Utility in Network Trace Anonymization
As network security monitoring grows more sophisticated, there is an
increasing need for outsourcing such tasks to third-party analysts. However,
organizations are usually reluctant to share their network traces due to
privacy concerns over sensitive information, e.g., network and system
configuration, which may potentially be exploited for attacks. In cases where
data owners are convinced to share their network traces, the data are typically
subjected to certain anonymization techniques, e.g., CryptoPAn, which replaces
real IP addresses with prefix-preserving pseudonyms. However, most such
techniques either are vulnerable to adversaries with prior knowledge about some
network flows in the traces, or require heavy data sanitization or
perturbation, both of which may result in a significant loss of data utility.
In this paper, we aim to preserve both privacy and utility through shifting the
trade-off from between privacy and utility to between privacy and computational
cost. The key idea is for the analysts to generate and analyze multiple
anonymized views of the original network traces; those views are designed to be
sufficiently indistinguishable even to adversaries armed with prior knowledge,
which preserves the privacy, whereas one of the views will yield true analysis
results privately retrieved by the data owner, which preserves the utility. We
present the general approach and instantiate it based on CryptoPAn. We formally
analyze the privacy of our solution and experimentally evaluate it using real
network traces provided by a major ISP. The results show that our approach can
significantly reduce the level of information leakage (e.g., less than 1\% of
the information leaked by CryptoPAn) with comparable utility
Biodiversity assessment following a naturality gradient of riverbank protection structures in French prealps rivers
Erosion control of riverbank is frequently necessary to protect human investments situated along rivers. The technique chosen for such erosion control construction may have major impacts on biodiversity and on the functioning of river corridors. Even if there is agreement, that biodiversity should be one criterion for choosing embankments techniques little is known about whether such techniques can accommodate biodiversity. We aimed to determine coleopteran and plant taxonomic diversities along a naturality gradient of riverbank protection systems, ranking from entirely civil engineering structures, through combined constructions (mixing civil engineering and bioengineering), to purely bioengineering structures. Fifteen sites (five sites of each technique) were sampled in the Rhône-Alpes region (S.E. France). On each site, vegetation was sampled along three transects from the bottom to the top of the riverbank and flying beetles by trapping. In total, we recorded 148 plant species and 78 beetle genera. We found significantly lower animal and plant diversities within civil engineering constructions than in the other two techniques. Diversities of both techniques tended to be higher, although not significantly, in combined techniques than in purely bioengineering ones. Furthermore, civil engineering structures were more subject to invasion by exotic plant species than the two other techniques. These results quantify and highlight the interest of bioengineering techniques compared to civil engineering in enhancing biodiversity and limiting invasive species techniques
Interstellar neutral helium in the heliosphere from IBEX observations. V. Observations in IBEX-Lo ESA steps 1, 2, & 3
Direct-sampling observations of interstellar neutral (ISN) He by Interstellar
Boundary Explorer (IBEX) provide valuable insight into the physical state of
and processes operating in the interstellar medium ahead of the heliosphere.
The ISN He atom signals are observed at the four lowest ESA steps of the
IBEX-Lo sensor. The observed signal is a mixture of the primary and secondary
components of ISN He and H. Previously, only data from one of the ESA steps
have been used. Here, we extended the analysis to data collected in the three
lowest ESA steps with the strongest ISN He signal, for the observation seasons
2009-2015. The instrument sensitivity is modeled as a linear function of the
atom impact speed onto the sensor's conversion surface separately for each ESA
step of the instrument. We found that the sensitivity increases from lower to
higher ESA steps, but within each of the ESA steps it is a decreasing function
of the atom impact speed. This result may be influenced by the hydrogen
contribution, which was not included in the adopted model, but seems to exist
in the signal. We conclude that the currently accepted temperature of ISN He
and velocity of the Sun through the interstellar medium do not need a revision,
and we sketch a plan of further data analysis aiming at investigating ISN H and
a better understanding of the population of ISN He originating in the outer
heliosheath.Comment: 20 pages, 5 figures, 5 tables, accepted for publication in the The
Astrophysical Journa
Métodos y técnicas de evaluación de la emoción, percepción y satisfacción de usuarios y consumidores: casos de estudio enfocados al Diseño Automotriz
Studies that aim to assess perception, emotion and satisfaction in relation to products, services, systems and interfaces are more and more common, demonstrating the interest of academia, market and industry in relation to the hedonic factors of the experience, in addition to the pragmatic factors.Los estudios que tienen como objetivo evaluar la percepción, la emoción y la satisfacción en relación con los productos, servicios, sistemas e interfaces son cada vez más comunes, lo que demuestra el interés de la academia, el mercado y la industria en relación con los factores hedónicos de la experiencia, además de los factores pragmáticos.Estudos que tem por objetivo avaliar a percepção, a emoção e a satisfação em relação à produtos, serviços, sistemas e interfaces estão cada vez mais comuns, demonstrando o interesse da academia, mercado e indústria em relação aos fatores hedônicos da experiência, para além dos fatores pragmáticos. 
- …