195 research outputs found

    Wavelet-Packet Powered Deepfake Image Detection

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    As neural networks become more able to generate realistic artificial images, they have the potential to improve movies, music, video games and make the internet an even more creative and inspiring place. Yet, at the same time, the latest technology potentially enables new digital ways to lie. In response, the need for a diverse and reliable toolbox arises to identify artificial images and other content. Previous work primarily relies on pixel-space CNN or the Fourier transform. To the best of our knowledge, wavelet-based gan analysis and detection methods have been absent thus far. This paper aims to fill this gap and describes a wavelet-based approach to gan-generated image analysis and detection. We evaluate our method on FFHQ, CelebA, and LSUN source identification problems and find improved or competitive performance.Comment: Source code is available at https://github.com/gan-police/frequency-forensic

    Implications of large dimuon CP asymmetry in B_{d,s} decays on minimal flavor violation with low tan beta

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    The D0 collaboration has recently announced evidence for a dimuon CP asymmetry in B_{d,s} decays of order one percent. If confirmed, this asymmetry requires new physics. We argue that for minimally flavor violating (MFV) new physics, and at low tan beta=v_u/v_d, there are only two four-quark operators (Q_{2,3}) that can provide the required CP violating effect. The scale of such new physics must lie below 260 GeV sqrt{tan beta}. The effect is universal in the B_s and B_d systems, leading to S_{psi K}~sin(2beta)-0.15 and S_{psi phi}~0.25. The effects on epsilon_K and on electric dipole moments are negligible. The most plausible mechanism is tree-level scalar exchange. MFV supersymmetry with low tan beta will be excluded. Finally, we explain how a pattern of deviations from the Standard Model predictions for S_{psi phi}, S_{psi K} and epsilon_K can be used to test MFV and, if MFV holds, to probe its structure in detail.Comment: 11 pages. v2: References adde

    Differential responses of trees to temperature variation during the chilling and forcing phases

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    AbstractTemperate-zone trees must fulfill cultivar-specific chilling and heat requirements during the dormant period, in order to produce leaves and flowers in the following growing season. Timing and accumulation rate of chill and heat are understood to determine the timing of spring events, but both processes are difficult to observe in dormant tree buds. Where long-term phenological observations are available, Partial Least Squares (PLS) regression offers a statistical opportunity to delineate phases of chill and heat accumulation and determine the climatic requirements of trees. This study uses PLS regression to explore how the timing of spring events of chestnut in China, cherry in Germany and walnut in California is related to variation in the daily rates of chill and heat accumulation, as calculated with horticultural models. Dependent variables were 39 years of flowering dates for chestnuts in Beijing (China), 25 years of cherry bloom in Klein-Altendorf (Germany) and 54 years of walnut leaf emergence in Davis (California, USA). These were related to daily accumulation rates of chill, calculated with the Dynamic Model, and heat, calculated with the Growing Degree Hours Model. Compared to an earlier version of the procedure, in which phenological dates were related to unprocessed temperature data, delineation of chilling and forcing phases was much clearer when using horticultural metrics to quantify chill and heat. Chestnut bloom in the cold-winter climate of Beijing was found to depend primarily on the rate of heat accumulation, while cherry bloom in the temperate climate of Germany showed dependence on both chill and heat accumulation rates. The timing of walnut leaf emergence in the mild-winter climate of California depended much more strongly on chill accumulation rates. Chilling (in Chill Portions=CP) and heat (in Growing Degree Hours=GDH) requirements determined based on PLS regression were 79.8±5.3 CP and 13,466±1918 GDH for chestnut bloom in Beijing, 104.2±8.9 CP and 2698±1183 GDH for cherry bloom in Germany, and 37.5±5.0 CP and 11,245±1697 GDH for walnut leaf emergence in California. Spring phases of cherry in Klein-Altendorf and especially chestnut in Beijing will likely continue to advance in response to global warming, while for walnut in California, inadequate chilling may cause delays in flowering and leaf emergence. Such delays could serve as an early-warning indicator that future productivity may be threatened by climate change. The R package ‘chillR’ makes the method used in this study available for wider use

    CP violation and limits on New Physics including recent BsB_s measurements

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    We analyse present constraints on the SM parameter space and derive, in a model independent way, various bounds on New Physics contributions to Bd0B_d^0--Bˉd0\bar B_d^0 and Bs0B_s^0--Bˉs0\bar B_s^0 mixings. Our analyses include information on a large set of asymmetries, leading to the measurement of the CKM phases Îł\gamma and ÎČˉ\bar\beta, as well as recent data from D0 and CDF related to the Bs0B_s^0--Bˉs0\bar B_s^0 system such as the measurement of ΔMBs\Delta M_{B_s}, ASLA_{SL} and ΔΓsCP\Delta\Gamma_{s}^{CP}. We examine in detail several observables such as the asymmetries AsldA_{sl}^d, ASLA_{SL}, the width differences ΔΓd\Delta\Gamma_{d} and ΔΓsCP\Delta\Gamma_{s}^{CP} and discuss the r\^ole they play in establishing the limits on New Physics. The present data clearly favour the SM, with the New Physics favoured region placed around the SM solution. A New Physics solution significantly different from the SM is still allowed, albeit quite disfavoured (2.6% probability). We analyse the presently available indirect knowledge on the phase χˉ\bar\chi entering in Bs0B_s^0--Bˉs0\bar B_s^0 mixing and study the impact of a future measurement of χˉ\bar\chi to be achieved at LHC, through the measurement of the time-dependent CP asymmetry in Bs→J/ΚΊB_s\to J/\Psi \Phi decays.Comment: 29 pages, 31 figures; updated analyses and reference

    Rare Decays as a Probe for New Physics

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    We discuss the indirect search for new degrees of freedom beyond the standard model, within flavour physics. In particular, we analyse the minimal flavour violation hypothesis and its phenomenological implications, especially the large-tan beta scenario in supersymmetric models, and also compare it with the constrained minimal flavour violation scenario. Moreover, we briefly discuss some recent progress in inclusive b to s transitions and present a status report of the so-called K-pi puzzle.Comment: 8 pages, 6 figures, based on an invited review talk given at Beauty 2006, the 11th International Conference on B physics at Hadron Colliders, September 2006, Oxford (England

    Cetuximab as Second-Line Therapy in Patients with Metastatic Esophageal Adenocarcinoma: A Phase II Southwest Oncology Group Study (S0415)

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    IntroductionEsophageal adenocarcinomas commonly express the epidermal growth factor receptor. This trial assessed the 6-month overall survival probability in metastatic esophageal cancer patients treated with cetuximab as second-line therapy.MethodsThis was a multicenter, open-label phase II study of single-agent cetuximab for metastatic esophageal adenocarcinoma patients who failed one prior chemotherapy regimen. Adequate organ function and Zubrod performance status of 0 to 2 were required. Patients received cetuximab 400 mg/m2 intravenously (IV) on week 1 and 250 mg/m2 IV weekly thereafter. The primary objective was to determine 6-month overall survival. Secondary end points included progression-free survival, response rate, and toxicity. Tumor tissue was collected for correlative studies.ResultsSixty-three patients were registered, with eight ineligible or never treated. Fifty-five eligible patients (49 men, 6 women; median age = 61.2 years [range, 30.7–88.5]) were enrolled. Twenty patients survived more than 6 months for a 6-month overall survival rate of 36% (95% confidence interval [CI]: 24–50%). The median overall survival was 4.0 months (95% CI: 3.2–5.9). Median progression-free survival was 1.8 months (95% CI: 1.7–1.9). One partial response and two unconfirmed partial responses were observed. Two patients experienced grade 4 fatigue. There was one treatment-related death due to pneumonitis. Germline polymorphisms of epidermal growth factor receptor, epidermal growth factor, interleukin (IL)-8, cyclooxygenase (COX)-2, vascular epidermal growth factor receptor (VEGF), CCND1, neuropilin 1 (NRP1), and K-ras mutational status were not associated with response or survival.ConclusionsThe 6-month overall survival rate of 36% observed on this study failed to meet the primary survival objective. Thus, cetuximab alone cannot be recommended in the second-line treatment of metastatic esophageal cancer

    A new CP violating observable for the LHC

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    We study a new type of CP violating observable that arises in three body decays that are dominated by an intermediate resonance. If two interfering diagrams exist with different orderings of final state particles, the required CP-even phase arises due to the different virtualities of the resonance in each of the two diagrams. This method can be an important tool for accessing new CP phases at the LHC and future colliders.Comment: 22 pages, v2: discussion of charged particle decays and a few references added v3: typos corrected, matches published versio
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