Advanced Hough-based method for on-device document localization

The demand for on-device document recognition systems increases in conjunction with the emergence of more strict privacy and security requirements. In such systems, there is no data transfer from the end device to a third-party information processing servers. The response time is vital to the user experience of on-device document recognition. Combined with the unavailability of discrete GPUs, powerful CPUs, or a large RAM capacity on consumer-grade end devices such as smartphones, the time limitations put significant constraints on the computational complexity of the applied algorithms for on-device execution. In this work, we consider document location in an image without prior knowledge of the docu-ment content or its internal structure. In accordance with the published works, at least 5 systems offer solutions for on-device document location. All these systems use a location method which can be considered Hough-based. The precision of such systems seems to be lower than that of the state-of-the-art solutions which were not designed to account for the limited computational resources. We propose an advanced Hough-based method. In contrast with other approaches, it accounts for the geometric invariants of the central projection model and combines both edge and color features for document boundary detection. The proposed method allowed for the second best result for SmartDoc dataset in terms of precision, surpassed by U-net like neural network. When evaluated on a more challenging MIDV-500 dataset, the proposed algorithm guaranteed the best precision compared to published methods. Our method retained the applicability to on-device computations.This work is partially supported by Russian Foundation for Basic Research (projects 18-29-26035 and 19-29-09092)

Покрытия на основе двумерно упорядоченного линейно-цепочечного углерода для защиты титановых имплантатов от микробной колонизации

Purpose of the study – to evaluate the antibacterial activity and biological compatibility of alloy coatings based on two-dimensionally ordered linear chain carbon (TDOLCC).Materials and Methods. Coatings based on TDOLCC were synthesized using alloying additions like nitrogen (TDOLCC+N) and silver (TDOLCC+Ag) on the surfaces of titanium plates and polystyrene plates by the ion-stimulated carbon condensation in a vacuum. The authors examined the superficial bactericidal activity of the coatings and its resistance to mechanical effects. Coated plates were evaluated in respect of rate of microbial biofilms formation by clinical isolates with multiple and extreme antibiotic resistance. Specimens were colored with crystal violet solution to visualize the biofilms. Cytotoxic effect of coatings was evaluated in respect of primary culture of fibroblasts and keratinocyte cell line HaCaT.Results. The authors observed pronounced superficial bactericidal effect of TDOLCC+Ag coating in respect of microorganisms of several taxonomic groups independently of their resistance to antibacterial drugs. TDOLCC+Ag coating proved capable to completely prevent microbial biofilm formation by antibiotic resistant clinical isolates of S. aureus and P. aeruginosa. Silvercontaining coating demonstrated mechanical resistance and preservation of close to baseline level of superficial bactericidal activity even after lengthy abrasion treatment. TDOLCC based coatings did not cause any cytotoxic effects. Structure of monolayers formed in cavities coated by TDOLCC+N and TDOLCC+Ag was indistinguishable from the monolayers in cavities of control plates.Цель исследования — оценить антибактериальную активность и биологическую совместимость легированных покрытий металлоконструкций для остеосинтеза на основе двумерно упорядоченного линейно-цепочечного углерода (ДУ ЛЦУ).Материал и методы. Методом ионно-стимулированной конденсации углерода в вакууме на поверхностях титановых пластин и полистироловых планшетов синтезированы покрытия на основе ДУ ЛЦУ с легирующими добавками: азотом (ДУ ЛЦУ+N) и серебром (ДУ ЛЦУ+Ag). Изучена поверхностная бактерицидная активность покрытий и ее устойчивость к механическим воздействиям. На пластинах с покрытиями оценена интенсивность формирования микробных биопленок клиническими изолятами микроорганизмов со множественной и экстремальной антибиотикорезистентностью, для визуализации сформированных биопленок выполнено окрашивание образцов раствором кристаллического фиолетового. Оценка цитотоксичности покрытий выполнена в отношении первичной культуры фибробластов и клеточной линии кератиноцитов HaCaT.Результаты. Выявлен выраженный поверхностный бактерицидный эффект покрытий ДУ ЛЦУ+Ag в отношении микроорганизмов нескольких таксономических групп, не зависящий от их устойчивости к антибактериальным препаратам. Для покрытия ДУ ЛЦУ+Ag установлена способность полного предотвращения формирования микробных биопленок антибиотико-резистентными клиническими изолятами S. aureus и P. aeruginosa. Показана механическая устойчивость серебросодержащего покрытия с сохранением уровня поверхностной бактерицидной активности, близкого к исходному, даже после продолжительной абразивной обработки. Покрытия на основе ДУ ЛЦУ не вызывали цитотоксических эффектов. Структура монослоя, сформированного в лунках с покрытиями ДУ ЛЦУ+N и ДУ ЛЦУ+Ag, была неотличима от лунок контрольных планшетов

Перифокальные реакции мягких тканей на введение контаминированных имплантатов с композиционным антибактериальным покрытием: экспериментальное исследование

Background. Protection against microbial colonization of surface fixators for metal osteosynthesis can reduce the number of infectious complications. The aim of the study was to experimentally assess early perifocal tissue reactions to metal implants with a composite antibacterial coating under microbial load. Methods. Fragments of steel pins for osteosynthesis (diameter 1 mm) with a four-component antibacterial coating based on polylactide, polyurethane, ciprofloxacin and silver nanoparticles were contaminated by methicillin-resistant S. aureus (MRSA) 43431. They were implanted in rats within the quadriceps femoris. Contaminated uncoated pins were used as a control. The animals were withdrawn from the experiment on the 2nd, 4th, 7th day after implantation. Histopathological specimens from tissue around implants were prepared. A semiquantitative assessment of reactions was performed. Results. The microbial load before implantation was (1.120.26)106 S. aureus cells for the control implants and (0.860.31)106 cells for implants with antibacterial coating. Tissue inflammatory reactions on the second day of implantation were equally evident in the control and investigated groups. There was a significant reduction in the number of immune cells and necrotic detritus, as well as increased growth of connective tissue and neoangiogenesis in the experimental group by the 4th day. The appearance of a less pronounced well-vascularized fibrous capsule around the experimental implants was noted by the 7th day. It indicates a more favorable healing of soft tissues in comparison with the control. Conclusion. Weak morphological manifestations of tissue reactions in response to the fitting of contaminated implants with an antibacterial coating can be associated with both the direct antimicrobial effect of the coating components and the anti-inflammatory activity of silver nanoparticles and ciprofloxacin included in its composition.Актуальность. Защита от микробной колонизации поверхности фиксаторов для металлоостеосинтеза способна сократить количество инфекционных осложнений. Цель исследования экспериментально оценить ранние перифокальные тканевые реакции на металлические имплантаты с композиционным антибактериальным покрытием в условиях микробной нагрузки. Материал и методы. Фрагменты стальных спиц для остеосинтеза диаметром 1 мм с нанесенным четырехкомпонентным антибактериальным покрытием на основе полилактида, полиуретана, ципрофлоксацина и наночастиц серебра контаминировали культурой метициллинорезистентного S. aureus (MRSA) 43431 и имплантировали крысам в толщу четырехглавой мышцы бедра. В качестве контрольных имплантировали контаминированные спицы без покрытия. На 2-е, 4-е и 7-е сут. после имплантации животных выводили из эксперимента. Готовили патогистологические препараты тканей вокруг имплантатов. Выполняли полуколичественную оценку тканевых реакций. Результаты. Микробная нагрузка перед имплантацией составляла (1,120,26)106 клеток S. aureus для контрольных имплантатов и (0,860,31)106 клеток для имплантатов с антибактериальным покрытием. Тканевые реакции воспалительного характера на 2-е сут. имплантации были одинаково выражены в контрольной и экспериментальной группах. К 4-м сут. отмечено значимое снижение количества иммунных клеток и некротического детрита, а также усиление разрастания соединительной ткани и неоангиогенеза в экспериментальной группе. К 7-м сут. отмечено появление менее выраженной, хорошо васкуляризованной фиброзной капсулы вокруг экспериментальных имплантатов, что указывает на более благоприятное заживление мягких тканей в сравнении с контролем. Заключение. Слабовыраженные морфологические проявления тканевых реакций в ответ на внедрение контаминированных имплантатов с антибактериальным покрытием могут быть связаны как с прямым противомикробным действием компонентов покрытия, так и с противовоспалительной активностью входящих в его состав наночастиц серебра и ципрофлоксацина

Measurement of \Gamma_{ee}(J/\psi)*Br(J/\psi->e^+e^-) and \Gamma_{ee}(J/\psi)*Br(J/\psi->\mu^+\mu^-)

The products of the electron width of the J/\psi meson and the branching fraction of its decays to the lepton pairs were measured using data from the KEDR experiment at the VEPP-4M electron-positron collider. The results are \Gamma_{ee}(J/\psi)*Br(J/\psi->e^+e^-)=(0.3323\pm0.0064\pm0.0048) keV, \Gamma_{ee}(J/\psi)*Br(J/\psi->\mu^+\mu^-)=(0.3318\pm0.0052\pm0.0063) keV. Their combinations \Gamma_{ee}\times(\Gamma_{ee}+\Gamma_{\mu\mu})/\Gamma=(0.6641\pm0.0082\pm0.0100) keV, \Gamma_{ee}/\Gamma_{\mu\mu}=1.002\pm0.021\pm0.013 can be used to improve theaccuracy of the leptonic and full widths and test leptonic universality. Assuming e\mu universality and using the world average value of the lepton branching fraction, we also determine the leptonic \Gamma_{ll}=5.59\pm0.12 keV and total \Gamma=94.1\pm2.7 keV widths of the J/\psi meson.Comment: 7 pages, 6 figure

New precise determination of the \tau lepton mass at KEDR detector

The status of the experiment on the precise $\tau$ lepton mass measurement running at the VEPP-4M collider with the KEDR detector is reported. The mass value is evaluated from the $\tau^+\tau^-$ cross section behaviour around the production threshold. The preliminary result based on 6.7 pb$^{-1}$ of data is $m_{\tau}=1776.80^{+0.25}_{-0.23} \pm 0.15$ MeV. Using 0.8 pb$^{-1}$ of data collected at the $\psi'$ peak the preliminary result is also obtained: $\Gamma_{ee}B_{\tau\tau}(\psi') = 7.2 \pm 2.1$ eV.Comment: 6 pages, 8 figures; The 9th International Workshop on Tau-Lepton Physics, Tau0

Search for narrow resonances in e+ e- annihilation between 1.85 and 3.1 GeV with the KEDR Detector

We report results of a search for narrow resonances in e+ e- annihilation at center-of-mass energies between 1.85 and 3.1 GeV performed with the KEDR detector at the VEPP-4M e+ e- collider. The upper limit on the leptonic width of a narrow resonance Gamma(R -> ee) Br(R -> hadr) < 120 eV has been obtained (at 90 % C.L.)

Measurement of main parameters of the \psi(2S) resonance

A high-precision determination of the main parameters of the \psi(2S) resonance has been performed with the KEDR detector at the VEPP-4M e^{+}e^{-} collider in three scans of the \psi(2S) -- \psi(3770) energy range. Fitting the energy dependence of the multihadron cross section in the vicinity of the \psi(2S) we obtained the mass value M = 3686.114 +- 0.007 +- 0.011 ^{+0.002}_{-0.012} MeV and the product of the electron partial width by the branching fraction into hadrons \Gamma_{ee}*B_{h} = 2.233 +- 0.015 +- 0.037 +- 0.020 keV. The third error quoted is an estimate of the model dependence of the result due to assumptions on the interference effects in the cross section of the single-photon e^{+}e^{-} annihilation to hadrons explicitly considered in this work. Implicitly, the same assumptions were employed to obtain the charmonium leptonic width and the absolute branching fractions in many experiments. Using the result presented and the world average values of the electron and hadron branching fractions, one obtains the electron partial width and the total width of the \psi(2S): \Gamma_{ee} =2.282 +- 0.015 +- 0.038 +- 0.021 keV, \Gamma = 296 +- 2 +- 8 +- 3 keV. These results are consistent with and more than two times more precise than any of the previous experiments

The Deuteron Spin-dependent Structure Function g1d and its First Moment

We present a measurement of the deuteron spin-dependent structure function g1d based on the data collected by the COMPASS experiment at CERN during the years 2002-2004. The data provide an accurate evaluation for Gamma_1^d, the first moment of g1d(x), and for the matrix element of the singlet axial current, a0. The results of QCD fits in the next to leading order (NLO) on all g1 deep inelastic scattering data are also presented. They provide two solutions with the gluon spin distribution function Delta G positive or negative, which describe the data equally well. In both cases, at Q^2 = 3 (GeV/c)^2 the first moment of Delta G is found to be of the order of 0.2 - 0.3 in absolute value.Comment: fits redone using MRST2004 instead of MRSV1998 for G(x), correlation matrix adde

Search for displaced vertices arising from decays of new heavy particles in 7 TeV pp collisions at ATLAS

We present the results of a search for new, heavy particles that decay at a significant distance from their production point into a final state containing charged hadrons in association with a high-momentum muon. The search is conducted in a pp-collision data sample with a center-of-mass energy of 7 TeV and an integrated luminosity of 33 pb^-1 collected in 2010 by the ATLAS detector operating at the Large Hadron Collider. Production of such particles is expected in various scenarios of physics beyond the standard model. We observe no signal and place limits on the production cross-section of supersymmetric particles in an R-parity-violating scenario as a function of the neutralino lifetime. Limits are presented for different squark and neutralino masses, enabling extension of the limits to a variety of other models.Comment: 8 pages plus author list (20 pages total), 8 figures, 1 table, final version to appear in Physics Letters