scholarly journals On safe post-selection for Bell tests with ideal detectors: Causal diagram approach

Quantum ◽  
2021 ◽  
Vol 5 ◽  
pp. 575
Author(s):  
Pawel Blasiak ◽  
Ewa Borsuk ◽  
Marcin Markiewicz
Keyword(s):  
Selection Bias ◽  
Broad Class ◽  
Standard Form ◽  
Bell Inequalities ◽  
Generation Process ◽  
Causal Process ◽  
Entanglement Generation ◽  
Spatially Distributed ◽  
Bell Nonlocality ◽  
High Level

Reasoning about Bell nonlocality from the correlations observed in post-selected data is always a matter of concern. This is because conditioning on the outcomes is a source of non-causal correlations, known as a selection bias, rising doubts whether the conclusion concerns the actual causal process or maybe it is just an effect of processing the data. Yet, even in the idealised case without detection inefficiencies, post-selection is an integral part of experimental designs, not least because it is a part of the entanglement generation process itself. In this paper we discuss a broad class of scenarios with post-selection on multiple spatially distributed outcomes. A simple criterion is worked out, called the all-but-one principle, showing when the conclusions about nonlocality from breaking Bell inequalities with post-selected data remain in force. Generality of this result, attained by adopting the high-level diagrammatic tools of causal inference, provides safe grounds for systematic reasoning based on the standard form of multipartite Bell inequalities in a wide array of entanglement generation schemes, without worrying about the dangers of selection bias. In particular, it can be applied to post-selection defined by single-particle events in each detection chanel when the number of particles in the system is conserved.

Automated Risk Scenario Generation Using System Functional and Structural Knowledge

2005 ◽  
Author(s):  
Hamed Nejad ◽  
Ali Mosleh
Keyword(s):  
Physical Structure ◽  
Primary Objective ◽  
Structural Knowledge ◽  
Scenario Generation ◽  
Generation Process ◽  
Functional Requirements ◽  
Risk Simulation ◽  
Risk Scenario ◽  
High Level ◽  
Difficult Situations

Simulation may be the most practical way to assess the risk of systems with complex behaviors such as those that include hardware, software and human elements. However, since under normal design conditions human-designed systems generally perform in familiar and expected ways, a typical simulation will frequently lead to known and anticipated results. As such, the simulation program wastes a lot of time on familiar results without generating new knowledge about the system’s vulnerabilities. In order to increase our knowledge of risk, it would be preferable to push the system toward its limits to test the system’s ability to handle more difficult situations. Such an approach can help system designers to better understand risky situations and close the vulnerability gaps in their design. The primary objective of this study is to develop a risk simulation Planner (SimpraPlan) which generates scenarios that can explore the system’s vulnerabilities and offer a superior assessment of the risks involved. The Planner uses high level engineering knowledge (including the functional requirements and physical structure of the system) to generate scenarios that can exploit the system’s vulnerabilities. In this paper, the scenario generation process is explained in detail and scenarios generated by the SimpraPlan are compared with those generated by classical approaches to risk assessment.

Investigation and Properties of the Discharge in Dielectric Barrier Reactors Decomposition of Toluene, o-Xylene, Trichloroethylene, and Their Mixture Using a BaTiO3 Packed-Bed Plasma Reactor

1996 ◽  
Vol 1 (1) ◽  
Author(s):  
Gerhard J. Pietsch
Keyword(s):  
Dielectric Barrier Discharge ◽  
Chemical Reactions ◽  
Barrier Discharge ◽  
Plasma Reactor ◽  
Packed Bed ◽  
Generation Process ◽  
Dielectric Barrier ◽  
Process Gas ◽  
Spatially Distributed ◽  
Quantitative Results

AbstractThe dielectric barrier discharge consists of numerous non-thermal microdischarges which are temporally and spatially distributed within the reactor volume. From a refined modeling of microdischarges, chemical reactions, and the interaction of discharges and process gas, the properties of the reactor can be evaluated. Quantitative results for the ozone generation process are presented.

Staged Catalytic Combustion Method for the Advanced Zero Emissions Gas Turbine Power Plant

2004 ◽  
Author(s):  
Timothy Griffin ◽  
Dieter Winkler ◽  
Markus Wolf ◽  
Christoph Appel ◽  
John Mantzaras
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Combustion Method ◽  
Significant Inhibition ◽  
Combustion Stability ◽  
Exhaust Gas ◽  
Generation Process ◽  
Combustion Properties ◽  
Gas Dilution ◽  
High Level

The AZEP (Advanced Zero Emissions Power Plant) project addresses the development of a novel “zero emissions,” gas turbine-based, power generation process to reduce CO2 emissions. Preliminary calculations indicate the attractiveness of this concept in comparison to conventional tail-end CO2 capture. Key to achieving the AZEP project targets is the development of a combustion system to burn natural gas with nearly stoichiometric amounts of oxygen and high levels of exhaust gas dilution. Within the first part of this study the fundamental combustion properties of AZEP gas mixtures are quantitatively determined. Significant inhibition results from the high level of exhaust gas dilution. In the second part a staged, rich–lean combustion concept, proposed to improve combustion stability, is investigated. It was shown that significant levels of hydrogen could be produced by a first stage, partial catalytic oxidation (PCO) of methane. Furthermore, it is shown that the addition of this produced hydrogen improves the stability of the downstream, second stage burnout zone. It was demonstrated that the produced syngas could act to reduce the blowout limit by ca. 100 K as compared to homogeneous gas phase combustion.

scholarly journals Image Captioning Based on Deep Neural Networks

2018 ◽  
Vol 232 ◽  
pp. 01052
Author(s):  
Shuang Liu ◽  
Liang Bai ◽  
Yanli Hu ◽  
Haoran Wang
Keyword(s):  
Neural Networks ◽  
Deep Neural Networks ◽  
Generation Process ◽  
Image Captioning ◽  
The Past ◽  
Representative Work ◽  
Computer Learn ◽  
High Level ◽  
Natural Language Process ◽  
The Relationship

With the development of deep learning, the combination of computer vision and natural language process has aroused great attention in the past few years. Image captioning is a representative of this filed, which makes the computer learn to use one or more sentences to understand the visual content of an image. The meaningful description generation process of high level image semantics requires not only the recognition of the object and the scene, but the ability of analyzing the state, the attributes and the relationship among these objects. Though image captioning is a complicated and difficult task, a lot of researchers have achieved significant improvements. In this paper, we mainly describe three image captioning methods using the deep neural networks: CNN-RNN based, CNN-CNN based and Reinforcement-based framework. Then we introduce the representative work of these three top methods respectively, describe the evaluation metrics and summarize the benefits and major challenges.

Experimental study of the coherent vorticity in slightly under-expanded supersonic screeching jets

2019 ◽  
Vol 18 (2-3) ◽  
pp. 207-230
Author(s):  
Bertrand Mercier ◽  
Thomas Castelain ◽  
Christophe Bailly
Keyword(s):  
Acoustic Waves ◽  
Jet Flows ◽  
Generation Process ◽  
Screech Tone ◽  
Round Jets ◽  
Image Velocimetry ◽  
Shock Motion ◽  
Peak Shock ◽  
High Level

The noise generation mechanism of screech tone by shock leakage in underexpended round jets is experimentally investigated by means of phase-averaged velocity fields. Two jet flows at Mach numbers 1.10 and 1.15 are measured by a particle image velocimetry apparatus simultaneously with their near acoustic fields and sorted according to their phase with respect to a screech period. The coherent vorticity fields are then computed and analyzed. They depict two distinct regions of high level of vorticity fluctuations. Thanks to the knowledge about shock leakage gathered in previous studies, the role of both regions in the acoustic generation process is identified and a region of the flow is recognized as suitable for emitting acoustic waves. Phase-averaged schlieren visualizations are also computed and used to determine the motion of the first five shocks over a screech period. For both jets, the peak shock motion is found at the fourth shock tip. This shock is also located in the region recognized as favorable for the shock leakage to be observed.

scholarly journals Smooth coalgebra: testing vector analysis

2015 ◽  
Vol 27 (7) ◽  
pp. 1195-1235
Author(s):  
DUSKO PAVLOVIC ◽  
BERTFRIED FAUSER
Keyword(s):  
Dynamical Systems ◽  
Differential Forms ◽  
Standard Form ◽  
The State ◽  
State Transitions ◽  
State Spaces ◽  
Practical Applications ◽  
Cotangent Bundles ◽  
High Level ◽  
Tangent Bundles

Processes are often viewed as coalgebras, with the structure maps specifying the state transitions. In the simplest case, the state spaces are discrete, and the structure map simply takes each state to the next states. But the coalgebraic view is also quite effective for studying processes over structured state spaces, e.g. measurable, or continuous. In the present paper, we consider coalgebras over manifolds. This means that the captured processes evolve over state spaces that are not just continuous, but also locally homeomorphic to normed vector spaces, and thus carry a differential structure. Both dynamical systems and differential forms arise as coalgebras over such state spaces, for two different endofunctors over manifolds. A duality induced by these two endofunctors provides a formal underpinning for the informal geometric intuitions linking differential forms and dynamical systems in the various practical applications, e.g. in physics. This joint functorial reconstruction of tangent bundles and cotangent bundles uncovers the universal properties and a high-level view of these fundamental structures, which are implemented rather intricately in their standard form. The succinct coalgebraic presentation provides unexpected insights even about the situations as familiar as Newton's laws.

scholarly journals Quantum violations in the Instrumental scenario and their relations to the Bell scenario

Quantum ◽  
2019 ◽  
Vol 3 ◽  
pp. 186 ◽  
Author(s):  
Thomas Van Himbeeck ◽  
Jonatan Bohr Brask ◽  
Stefano Pironio ◽  
Ravishankar Ramanathan ◽  
Ana Belén Sainz ◽  
...  
Keyword(s):  
Opposite Direction ◽  
Causal Structure ◽  
Bell Inequalities ◽  
Quantum Correlations ◽  
Causal Models ◽  
Classical Quantum ◽  
Bell Nonlocality ◽  
Causal Structures

The causal structure of any experiment implies restrictions on the observable correlations between measurement outcomes, which are different for experiments exploiting classical, quantum, or post-quantum resources. In the study of Bell nonlocality, these differences have been explored in great detail for more and more involved causal structures. Here, we go in the opposite direction and identify the simplest causal structure which exhibits a separation between classical, quantum, and post-quantum correlations. It arises in the so-called Instrumental scenario, known from classical causal models. We derive inequalities for this scenario and show that they are closely related to well-known Bell inequalities, such as the Clauser-Horne-Shimony-Holt inequality, which enables us to easily identify their classical, quantum, and post-quantum bounds as well as strategies violating the first two. The relations that we uncover imply that the quantum or post-quantum advantages witnessed by the violation of our Instrumental inequalities are not fundamentally different from those witnessed by the violations of standard inequalities in the usual Bell scenario. However, non-classical tests in the Instrumental scenario require fewer input choices than their Bell scenario counterpart, which may have potential implications for device-independent protocols.

Scotch

2020 ◽  
Vol 14 (3) ◽  
pp. 281-293
Author(s):  
Martin Kiefer ◽  
Ilias Poulakis ◽  
Sebastian Breß ◽  
Volker Markl
Keyword(s):  
Energy Efficiency ◽  
Large Scale ◽  
Broad Class ◽  
Approximate Query Processing ◽  
Code Generator ◽  
Domain Specific ◽  
Large Scale Network ◽  
Hardware Description ◽  
Definition Of ◽  
High Level

Sketching algorithms are a powerful tool for single-pass data summarization. Their numerous applications include approximate query processing, machine learning, and large-scale network monitoring. In the presence of high-bandwidth interconnects or in-memory data, the throughput of summary maintenance over input data becomes the bottleneck. While FPGAs have shown admirable throughput and energy-efficiency for data processing tasks, developing FPGA accelerators requires a sophisticated hardware design and expensive manual tuning by an expert. We propose Scotch, a novel system for accelerating sketch maintenance using FPGAs. Scotch provides a domain-specific language for the user-friendly, high-level definition of a broad class of sketching algorithms. A code generator performs the heavy-lifting of hardware description, while an auto-tuning algorithm optimizes the summary size. Our evaluation shows that FPGA accelerators generated by Scotch outperform CPU- and GPU-based sketching by up to two orders of magnitude in terms of throughput and up to a factor of five in terms of energy efficiency.

Flow and Dipole Source Evaluation of a Generic SUV

2010 ◽  
Vol 132 (5) ◽  
Author(s):  
Jonas Ask ◽  
Lars Davidson
Keyword(s):  
Strouhal Number ◽  
Mesh Generation ◽  
Recirculation Zone ◽  
Dynamic Pressure ◽  
Pressure Sensors ◽  
Dipole Source ◽  
Generation Process ◽  
Source Terms ◽  
Side Window ◽  
High Level

Accurately predicting both average flow quantities and acoustic sources at the front window of today’s ground vehicles are still a considerable challenge to automotive companies worldwide. One of the most important aspects in terms of obtaining not only trustworthy results but also the most tedious one and therefore perhaps overlooked, is the control and outcome of the mesh generation process. Generating unstructured volume meshes suitable for large eddy simulations with high level representation of geometrical details is both a time consuming and an extremely computer demanding activity. This work investigates two different mesh generation processes with its main aim to evaluate their outcome with respect to the prediction of the two dominating dipole sources in a temporal form of the Curle’s equation. Only a handful of papers exists that report a high level representation of the vehicle geometry and the aim of predicting the fluctuating exterior noise sources. To the author’s knowledge no studies have been conducted in which both these source terms are evaluated quantitatively against measurements. The current paper investigates the degree to which the amplitude of these two source terms can be predicted by using the traditional law-of-the-wall and hex-dominant meshes with isotropic resolution boxes for a detailed ground vehicle geometry. For this purpose, the unstructured segregated commercial FLUENT finite volume method code is used. The flow field is treated as incompressible and the Smagorinsky–Lilly model is used to compute the subgrid stresses. Mean flow quantities are measured with a 14 hole probe for 14 rakes downstream of the side mirror. The dynamic pressure sensors are distributed at 16 different positions over the side window to capture the fluctuating pressure signals. All measurements in this work were conducted at Ford’s acoustic wind tunnel in Cologne. All three simulations accurately predict the velocity magnitude closest to the window and downstream of the mirror head recirculation zone. Some variations in the size and shape of this recirculation zone are found between the different meshes, most probably caused by differences in the detachment of the mirror head boundary layer. The Strouhal number of the shortest simulation was computed from the fundamental frequency of the drag force coefficient. The computed Strouhal number agrees well with the corresponding results from similar objects and gives an indication of an acceptable simulation time. The dynamic pressure sensors at 16 different locations at the vehicle side window were also used to capture the levels of the two dipole source terms. These results are compared with the three simulations. With the exception of three positions, at least one of the three simulations accurately captures the levels of both source terms up to about 1000 Hz. The three positions with less agreement as compared with measurements were found to be in regions sensitive to small changes in the local flow direction.

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