Efficient generation of universal two-dimensional cluster states with hybrid systems

We present a scheme to generate two-dimensional cluster state efficiently. The number of the basic gate-entangler-for the operation is in the order of the entanglement bonds of a cluster state, and could be reduced greatly if one uses them repeatedly. The scheme is deterministic and uses few ancilla resources and no quantum memory. It is suitable for large-scale quantum computation and feasible with the current experimental technology.Comment: 6 pages, 5 figure

Real-Time Salient Closed Boundary Tracking via Line Segments Perceptual Grouping

This paper presents a novel real-time method for tracking salient closed boundaries from video image sequences. This method operates on a set of straight line segments that are produced by line detection. The tracking scheme is coherently integrated into a perceptual grouping framework in which the visual tracking problem is tackled by identifying a subset of these line segments and connecting them sequentially to form a closed boundary with the largest saliency and a certain similarity to the previous one. Specifically, we define a new tracking criterion which combines a grouping cost and an area similarity constraint. The proposed criterion makes the resulting boundary tracking more robust to local minima. To achieve real-time tracking performance, we use Delaunay Triangulation to build a graph model with the detected line segments and then reduce the tracking problem to finding the optimal cycle in this graph. This is solved by our newly proposed closed boundary candidates searching algorithm called "Bidirectional Shortest Path (BDSP)". The efficiency and robustness of the proposed method are tested on real video sequences as well as during a robot arm pouring experiment.Comment: 7 pages, 8 figures, The 2017 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2017) submission ID 103

On the Performance of Multi-tier Heterogeneous Cellular Networks with Idle Mode Capability

This paper studies the impact of the base station (BS) idle mode capability (IMC) on the network performance of multi-tier and dense heterogeneous cellular networks (HCNs). Different from most existing works that investigated network scenarios with an infinite number of user equipments (UEs), we consider a more practical setup with a finite number of UEs in our analysis. More specifically, we derive the probability of which BS tier a typical UE should associate to and the expression of the activated BS density in each tier. Based on such results, analytical expressions for the coverage probability and the area spectral efficiency (ASE) in each tier are also obtained. The impact of the IMC on the performance of all BS tiers is shown to be significant. In particular, there will be a surplus of BSs when the BS density in each tier exceeds the UE density, and the overall coverage probability as well as the ASE continuously increase when the BS IMC is applied. Such finding is distinctively different from that in existing work. Thus, our result sheds new light on the design and deployment of the future 5G HCNs.Comment: conference submissio

A Linear Model Predictive Planning Approach for Overtaking Manoeuvres Under Possible Collision Circumstances

Overtaking is one of the most difficult tasks during driving. This manoeuvre demands good skills to accomplish it correctly. In the overtaking considering multiple vehicles (more than a couple) is necessary to understand, predict and coordinate future actions of the other participants. These reasons make it a significant scenario for testing in the connected and automated driving field, with the main goal of predicting safe future states. In this sense, this work presents an overtaking method based on a linear Model Predictive Control (MPC) approach, which considers multiple participants involved in the scenario. This method adapts dynamically the trajectory for the manoeuvre in case of unexpected situations. Some of these changes consider other vehicles coming on the opposite lane or variations on participants' driving decisions. Additionally, the system considers passengers' comfort, the vehicle physical constraints and lateral actions of the vehicle decoupled of the longitudinal ones to simplify the problem.European Commision H2020, (643921), UnCoVerCP

Effective Theory of Braid Excitations of Quantum Geometry in terms of Feynman Diagrams

We study interactions amongst topologically conserved excitations of quantum theories of gravity, in particular the braid excitations of four-valent spin networks. These have been shown previously to propagate and interact under evolution rules of spin foam models. We show that the dynamics of these braid excitations can be described by an effective theory based on Feynman diagrams. In this language, braids which are actively interacting are analogous to bosons, in that the topological conservation laws permit them to be singly created and destroyed. Exchanges of these excitations give rise to interactions between braids which are charged under the topological conservation rules.Comment: 23 pages, 7 figures. Accepted by Nucl. Phys.

Dijet resonance from leptophobic Z' and light baryonic cold dark matter

In light of the recent CDF report on the excess in the Wjj channel, we analyze (non)supersymmetric U(1)_B x U(1)_L model, interpreting the dijet peak as a leptophobic U(1)_B gauge boson. If this excess is confirmed, it has an interesting implication for the baryonic cold dark matter (CDM) in the model: there should be light CDM with a few GeV mass, and direct detection cross section at the level of a few x 10^{-2} pb.Comment: 5 pages, 3 figures, version published in Phys. Lett.

Anticipated synchronization in coupled chaotic maps with delays

We study the synchronization of two chaotic maps with unidirectional (master-slave) coupling. Both maps have an intrinsic delay $n_1$, and coupling acts with a delay $n_2$. Depending on the sign of the difference $n_1-n_2$, the slave map can synchronize to a future or a past state of the master system. The stability properties of the synchronized state are studied analytically, and we find that they are independent of the coupling delay $n_2$. These results are compared with numerical simulations of a delayed map that arises from discretization of the Ikeda delay-differential equation. We show that the critical value of the coupling strength above which synchronization is stable becomes independent of the delay $n_1$ for large delays.Comment: 10 pages, 4 figure

Wind tunnel experiments to teach physics

Innovative teaching experimental activities for secondary school students have been developed in order to introduce some aerodynamic concepts, with the aim of making science subjects such as mathematics and physics more attractive. Post-graduate students of Universidad Politécnica de Madrid (UPM) and teachers of Deutsche Schule Madrid (DSM) have constructed a small wind tunnel. The main goal has been to provide a tool for secondary school students to become familiar with the scientific method developing curiosity, imagination, initiative, critical thinking and problem-solving skills. Students of DSM have performed wind tunnel experiments, resulting in a successful and amusing experience. The students were able to relate the experimental results obtained with the physic principle of flight, previously explained in class. Evaluations reveal that both, the teacher and the students, considered the experience as interesting and helpful to lead with teaching physics, mathematics and engineering sciences. The teacher observed the strong motivation factor developed for the students to continue learning engineering sciences. Some of the students expressed that this experience had changed their prejudices about physics and mathematics, based only on theoretical approaches

Combining Direct & Indirect Kaon CP Violation to Constrain the Warped KK Scale

The Randall-Sundrum (RS) framework has a built in protection against flavour violation, but still generically suffers from little CP problems. The most stringent bound on flavour violation is due to epsilon_K, which is inversely proportional to the fundamental Yukawa scale. Hence the RS epsilon_K problem can be ameliorated by effectively increasing the Yukawa scale with a bulk Higgs, as was recently observed in arXiv:0810.1016. We point out that incorporating the constraint from epsilon'/\epsilon_K, which is proportional to the Yukawa scale, raises the lower bound on the KK scale compared to previous analyses. The bound is conservatively estimated to be 5.5 TeV, choosing the most favorable Higgs profile, and 7.5 TeV in the two-site limit. Relaxing this bound might require some form of RS flavour alignment. As a by-product of our analysis, we also provide the leading order flavour structure of the theory with a bulk Higgs.Comment: 15 pages, 2 figure

Cognitive Composite Score Association With Alzheimer\u27S Disease Plaque And Tangle Pathology

Background: Cognitive composite scores are used as the primary outcome measures for Alzheimer\u27s disease (AD) prevention trials; however, the extent to which these composite measures correlate with AD pathology has not been fully investigated. Since many on-going AD prevention studies are testing therapies that target either amyloid or tau, we sought to establish an association between a cognitive composite score and the underlying pathology of AD. Methods: Data from 192 older deceased and autopsied persons from the Rush Religious Order Study were used in this study. All participants were classified at their initial evaluations with a clinical diagnosis of no cognitive impairment (NCI). Of these individuals, 105 remained NCI at the time of their death while the remaining 87 progressed to mild cognitive impairment (MCI) or AD. A cognitive composite score composed of eight cognitive tests was used as the outcome measure. Individuals were classified into groups based on Consortium to Establish a Registry for Alzheimer\u27s Disease (CERAD) neuropathological diagnosis and Braak stage. Results: The rate of annualized composite score decline was significantly greater for the high CERAD (p \u3c 0.001, d = 0.56) and Braak (p \u3c 0.001, d = 0.55) groups compared with the low CERAD and Braak groups, respectively. Mixed-model repeated measure (MMRM) analyses revealed a significantly greater difference in composite score change from baseline for the high CERAD group relative to the low CERAD group after 5 years (Δ = -2.74, 95% confidence interval (CI) -5.01 to -0.47; p = 0.02). A similar analysis between low and high Braak stage groups found no significant difference in change from baseline (Δ = -0.69, 95% CI -3.03 to 1.66; p = 0.56). Conclusions: These data provide evidence that decreased cognitive composite scores were significantly associated with increased AD pathology and provide support for the use of cognitive composite scores in AD prevention trials