Emergent Gauge Field for a Chiral Bound State on Curved Surface

In this letter we show that there emerges a gauge field for two attractive particles moving on a curved surface when they form a chiral bound state. By solving a two-body problem on a sphere, we show explicitly that the center-of-mass wave functions of such deeply bound states are monopole harmonics instead of spherical harmonics. This indicates that the bound state experiences a gauge field identical to a magnetic monopole at the center of the sphere, with the monopole charge equal to the quantized relative angular momentum of this bound state. We show that this emergent gauge field is due to the coupling between the center-of-mass and the relative motion on curved surfaces. Our results can be generalized to an arbitrary curved surface where the emergent magnetic field is exactly the local Gaussian curvature. This result establishes an intriguing connection between space curvature and gauge field, paves an alternative way to engineer topological state with space curvature, and may be observed in cold atom system.Comment: 5 pages, 3 figures, 1 appendi

Implications of dark matter cascade decay from DAMPE, HESS, Fermi-LAT and AMS02 data

Recent high-energy cosmic $e^\pm$ measurement from the DArk Matter Particle Explorer (DAMPE) satellite confirms the deviation of total cosmic ray electron spectrum above 700-900 GeV from a simple power law. In this paper we demonstrate that the cascade decay of dark matter (DM) can account for DAMPE's TeV $e^+e^-$ spectrum. We select the least constraint DM decay channel into four muons as the benchmark scenario, and perform an analysis with propagation variance in both DM signal and the Milky Way's electron background. The best-fit of the model is obtained for joint DAMPE, Fermi-Large Area Telescope (Fermi-LAT), High Energy Stereoscopic System (HESS), high energy electron data sets, and with an $\mathcal{O}(10^{26})$ second decay lifetime, which is consistent with existing gamma ray and cosmic microwave background limits. We compare the spectral difference between the cascade decay of typical final-state channels. The least constrained $4\mu$ channels give good fits to the electron spectrum's TeV scale down-turn, yet their low energy spectrum has tension with sub-TeV positron data from AMS02. We also consider a three-step cascade decay into eight muons, and also a gamma-ray constrained $4\mu,4b$ mixed channel, to demonstrate that a further softened cascade decay signal would be required for the agreement with all the data sets.Comment: 8 pages, 1 table, 4 figure

A Precise Calculation of Delayed Coincidence Selection Efficiency and Accidental Coincidence Rate

A model is proposed to address issues on the precise background evaluation due to the complex data structure defined by the delayed coincidence method, which is widely used in reactor electron-antineutrino oscillation experiments. In this model, the effects from the muon veto, uncorrelated random background, coincident signal and background are all studied with the analytical solutions, simplifying the estimation of the systematic uncertainties of signal efficiency and accidental background rate determined by the unstable single rate. The result of calculation is validated numerically with a number of simulation studies and is also applied and validated in the recent Daya Bay hydrogen-capture based oscillation measurement

Bayesian Estimation Based Load Modeling Report

This report presents the detailed steps of establishing the composite load model in the power system. The derivations of estimation the ZIP model and IM model parameters are proposed in this report. This is a supplementary material for the paper submitted to PES GM 2019

Better Data Labelling with EMBLEM (and how that Impacts Defect Prediction)

Standard automatic methods for recognizing problematic development commits can be greatly improved via the incremental application of human+artificial expertise. In this approach, called EMBLEM, an AI tool first explore the software development process to label commits that are most problematic. Humans then apply their expertise to check those labels (perhaps resulting in the AI updating the support vectors within their SVM learner). We recommend this human+AI partnership, for several reasons. When a new domain is encountered, EMBLEM can learn better ways to label which comments refer to real problems. Also, in studies with 9 open source software projects, labelling via EMBLEM's incremental application of human+AI is at least an order of magnitude cheaper than existing methods ($\approx$ eight times). Further, EMBLEM is very effective. For the data sets explored here, EMBLEM better labelling methods significantly improved $P_{opt}20$ and G-scores performance in nearly all the projects studied here.Comment: 17 pages, 2 pages references, submitted for TSE journa

FLASH: A Faster Optimizer for SBSE Tasks

Most problems in search-based software engineering involve balancing conflicting objectives. Prior approaches to this task have required a large number of evaluations- making them very slow to execute and very hard to comprehend. To solve these problems, this paper introduces FLASH, a decision tree based optimizer that incrementally grows one decision tree per objective. These trees are then used to select the next best sample. This paper compares FLASH to state-of-the-art algorithms from search-based SE and machine learning. This comparison uses multiple SBSE case studies for release planning, configuration control, process modeling, and sprint planning for agile development. FLASH was found to be the fastest optimizer (sometimes requiring less than 1% of the evaluations used by evolutionary algorithms). Also, measured in terms of model size, FLASH's reasoning was far more succinct and comprehensible. Further, measured in terms of finding effective optimization, FLASH's recommendations were highly competitive with other approaches. Finally, FLASH scaled to more complex models since it always terminated (while state-of-the-art algorithm did not).Comment: 11 pages, 11 figure

A Covert Data Transport Protocol

Both enterprise and national firewalls filter network connections. For data forensics and botnet removal applications, it is important to establish the information source. In this paper, we describe a data transport layer which allows a client to transfer encrypted data that provides no discernible information regarding the data source. We use a domain generation algorithm (DGA) to encode AES encrypted data into domain names that current tools are unable to reliably differentiate from valid domain names. The domain names are registered using (free) dynamic DNS services. The data transmission format is not vulnerable to Deep Packet Inspection (DPI).Comment: 8 pages, 10 figures, conferenc

Universal Trimers induced by Spin-Orbit Coupling in Ultracold Fermi Gases

In this letter we address the issue how synthetic spin-orbit (SO) coupling can strongly affect three-body physics in ultracold atomic gases. We consider a system which consists of three fermionic atoms, including two spinless heavy atoms and one spin-1/2 light atom subjected to an isotropic SO coupling. We find that SO coupling can induce universal three-body bound states with negative s-wave scattering length at a smaller mass ratio, where no trimer bound state can exist if in the absence of SO coupling. The energies of these trimers are independent of high-energy cutoff, and therefore they are universal ones. Moreover, the resulting atom-dimer resonance can be effectively controlled by SO coupling strength. Our results can be applied to systems like ${}^6$Li and ${}^{40}$K mixture.Comment: 7 pages, 4 figure

Better Technical Debt Detection via SURVEYing

Software analytics can be improved by surveying; i.e. rechecking and (possibly) revising the labels offered by prior analysis. Surveying is a time-consuming task and effective surveyors must carefully manage their time. Specifically, they must balance the cost of further surveying against the additional benefits of that extra effort. This paper proposes SURVEY0, an incremental Logistic Regression estimation method that implements cost/benefit analysis. Some classifier is used to rank the as-yet-unvisited examples according to how interesting they might be. Humans then review the most interesting examples, after which their feedback is used to update an estimator for estimating how many examples are remaining. This paper evaluates SURVEY0 in the context of self-admitted technical debt. As software project mature, they can accumulate "technical debt" i.e. developer decisions which are sub-optimal and decrease the overall quality of the code. Such decisions are often commented on by programmers in the code; i.e. it is self-admitted technical debt (SATD). Recent results show that text classifiers can automatically detect such debt. We find that we can significantly outperform prior results by SURVEYing the data. Specifically, for ten open-source JAVA projects, we can find 83% of the technical debt via SURVEY0 using just 16% of the comments (and if higher levels of recall are required, SURVEY0can adjust towards that with some additional effort).Comment: 10 pages, 4 figures, 4 tables, conferenc

Kinematic signatures of reverberation mapping of close binaries of supermassive black holes in active galactic nuclei

Close binaries of supermassive black holes (CB-SMBHs) with separations of $\lesssim 0.1$pc as the final stage of galaxy mergers are sources of low frequency gravitational waves (GW), however, they are still elusive observationally because they are not spatially resolved. Fortunately, reverberation as echoes of broad emission lines to ionizing continuum conveys invaluable information of the dynamics of broad-line regions (BLRs) governed by supermassive black holes in the central regions of active galactic nuclei (AGNs). In this paper, we demonstrate how to composite the hybrid 2-dimensional transfer functions of binary BLRs around the CB-SMBHs in AGNs, providing an opportunity of identifying them from reverberation mapping (RM) data. It is found that there are variation-coupling effects in the transfer functions, arising from the coupling of CB-SMBH light curves in the Fourier space. We provide semi-analytical formulations of the transfer functions for kinematic maps of the gas. For cases with the simplest variation-coupling effects, we make calculations for several BLR models and reveal significant distinctions from those of single active black holes. In principle, the difference is caused by the orbital motion of the CB-SMBH systems. In order to search for CB-SMBHs in time-domain space, selection of target candidates should focus on local AGNs with H$\beta$ double-peaked profiles and weaker near-infrared emission. High-fidelity RM-campaigns of monitoring the targets in future will provide opportunities to reveal these kinematic signatures of the CB-SMBHs and hence for measurements of their orbital parameters.Comment: 22 pages, 8 figures, Accepted by The Astrophysical Journa