Search

We consider the problem of generating interpretable recommendations by identifying overlapping co-clusters of clients and products, based only on positive or implicit feedback. Our approach is applicable on very large datasets because it exhibits almost linear complexity in the input examples and the number of co-clusters. We show, both on real industrial data and on publicly available datasets, that the recommendation accuracy of our algorithm is competitive to that of state-of-the-art matrix factorization techniques. In addition, our technique has the advantage of offering recommendations that are textually and visually interpretable. Our formulation can also address cold-start problems by gracefully meshing collaborative and content-based reasoning. Finally, we present efficient Graphical Processing Unit (GPU) implementations and demonstrate a speedup of more than 270 times over our baseline CPU implementation on a cluster of 16 GPUs.

The phenomenon of quasi-complete separation that appears in the identification of the neuromuscular system called muscle spindle by a logistic regression model is considered. The system responds when it is affected by a number of stimuli. Both the response and the stimuli are very long binary sequences of events. In the logistic model, three functions are of special interest: the threshold, the recovery and the summation functions. The maximum likelihood estimates are obtained efficiently and very fast by using the penalized likelihood function. A validity test for the fitted model based on the randomized quantile residuals is proposed. The validity test is transformed to a goodness of fit test and the use of Q–Q plot is also discussed.

Following the rapid technology development on smart and electronic textiles, research on textile antennas has rapidly emerged during the last decade due to their numerous applications in the health and safety sectors. Integrated electronic components in textile structures enables the development of new products and services for commercial and tactical applications. Correspondingly, antenna systems that are either embedded in clothing or developed using textile materials are needed. However, the inherent impairments of antenna operability when integrated into garments (i.e. bending and crumbling due to the user’s mobility) make the development of textile antennas a challenging task. Another important issue is the operation of antennas in close vicinity to the human body, which can be modeled as a large volume with electrical properties different than those of air. In this paper, we report a linear spiral antenna design with a sufficiently large bandwidth to support wireless communications in a multitude of available networks, and also the potential to be used for body scanning and medical imaging through microwave transmission and scattering measurements.

Electromagnetic radiation influences in many ways humans and animals, while earthquakes are known to be related with electromagnetic phenomena. We recently showed that large earthquakes reduced admissions of psychiatric patients, whereas small earthquakes were associated with increased number of admissions. Our aim was to examine the effect of seismic-related electromagnetic activity on two chronic and severe psychiatric disorders varying in terms of etiology and treatment, i.e. bipolar disorder and schizophrenia. Retrospective data concerning monthly admission rates of patients diagnosed with schizophrenia or bipolar disorder in the Psychiatric Unit of the University Hospital of Heraklion, Crete, Greece between 2008 and 2010 were analyzed in relation to the number of earthquakes with small (≥2) or larger magnitude in the Crete region in Greece. Results showed a marked reduction of acute admissions during a storm of large earthquakes, which was greater in patients with bipolar disorder (91.2%) than schizophrenia patients (52.4%). In addition there was a significant increase of admissions during a period of frequent small earthquakes, primarily among patients with bipolar disorder. The results suggest that electrostatic fields that accompany large earthquakes may have a protective effect on psychiatric disorders, particularly on bipolar disorder. These findings are consistent with the ameliorating effect of electromagnetic fields used in Electroconvulsive therapy (ECT) and Transcranial Magnetic Stimulation (TMS) in patients with bipolar disorder. Future studies focusing on the underlying mechanisms may lead to more specific treatments of psychiatric disorders.

In the past two decades the world experienced an exceptional number of unprecedented extreme weather events, some causing major human suffering and economic damage, such as the March 2012 heat event, which was called “Meteorological March Madness.” From the beginning of space era a correlation of solar flares with pressure changes in atmosphere within 2–3 days or even less was reported. In this study we wanted to test the possible relation of highly warm weather events in North-East America with Solar Energetic Particle (SEP) events. For this reason we compared ground temperatures TM in Madison, Wisconsin, with energetic particle fluxes P measured by the EPAM instrument onboard the ACE spacecraft. In particular, we elaborated case events and the results of a statistical study of the SEP events related with the largest (Dst ≤ −150nT) Coronal Mass Ejection (CME)-induced geomagnetic storms, between with the years 1997–2015. The most striking result of our statistical analysis is a very significant positive correlation between the highest temperature increase. ΔTM and the time duration of the temperature increase ΔTM (r = 0.8, p

The emergence of cloud-based storage services is opening up new avenues in data exchange and data dissemination. This has amplified the interest in right-protection mechanisms to establish ownership in the event of data leakage. Current right-protection technologies, however, rarely provide strong guarantees on dataset utility after the protection process. This work presents techniques that explicitly address this topic and provably preserve the outcome of certain mining operations. In particular, we take special care to guarantee that the outcome of hierarchical clustering operations remains the same before and after right protection. Our approach considers all prevalent hierarchical clustering variants: single-, complete-, and average-linkage. We imprint the ownership in a dataset using watermarking principles, and we derive tight bounds on the expansion/contraction of distances incurred by the process. We leverage our analysis to design fast algorithms for right protection without exhaustively searching the vast design space. Finally, because the right-protection process introduces a user-tunable distortion on the dataset, we explore the possibility of using this mechanism for data obfuscation. We quantify the tradeoff between obfuscation and utility for spatiotemporal datasets and discover very favorable characteristics of the process. An additional advantage is that when one is interested in both right-protecting and obfuscating the original data values, the proposed mechanism can accomplish both tasks simultaneously.

Let $(M,d)$ be a bounded countable metric space and $c>0$ a constant, such that $d(x,y)+d(y,z)-d(x,z) \ge c$, for any pairwise distinct points $x,y,z$ of $M$. For such metric spaces we prove that they can be isometrically embedded into any Banach space containing an isomorphic copy of $\ell_\infty$., to appear in Comment.Math.Univ.Carolin

We compared the number of M > 2 earthquakes in an area, including the island of Crete, Greece, to the number of admissions to the Psychiatric Inpatient Unit of the University of Crete (IPU/UoC), during the period 2008–2010. We found that when earthquakes with M 6.4 occurred in the region examined, the number of monthly admissions to the Acute Care Unit of the IPU/UoC, NAA, reached lowest values, whereas this number increased when the monthly number NE of small (M < 3) earthquakes increased. We also found a positive correlation between the total number of monthly admissions NA and NE (r = 0.601/P = 0.001). When a daily resolution analysis was performed for the month with the highest value of NE, we found that an abrupt increase in the number of small earthquakes was followed by an increase in the number of admissions after ∼2 days (during that month, from a total of 71 patients, 38/10 people were diagnosed with schizophrenia/bipolar disorder). We hypothesize that seismic activity might be a significant contributing factor influencing the frequency of admissions of psychotic disorders in Crete in the period 2008–2010 and that the beneficial/adverse effects are related to the anomalous electric field/extra low frequency–ultra low frequency emissions.

When monitoring complex evolving systems a question that often arises is to detect causal chains of events. Do particular inputs force the system to produce new events or prohibits them? This can be also considered as a risk assessment for the systems response. In this work we present two methods of estimating the effect of multiple inputs on a complex neurophysiological system. Both the response and the stimuli are very long binary time series. The first approach is a non-parametric one and describes the linear and the non-linear association of the stationary point processes by estimating the second- and third-order cumulant density functions. The second approach is a parametric one and the association between the inputs and the response of the system is described by a logistic regression model which takes into account the system’s internal processes.

In this Letter we present additional experimental characteristics of anomalous soft photon radiation observed in π−p interactions at 280 GeV/c in the CERN experiment WA91, together with a re-calculated ratio of the observed direct soft photon signal to the expected level of the hadronic inner bremsstrahlung, which is found to be 5.3±1.0. The other presented characteristics, energy dependence and angular distributions of direct soft photons, show the similarity of the observed signal to the expected hadronic bremsstrahlung behaviour.

Recent results from the CERN Omega spectrometer on the enhancement of strange and multiply strange particle production in nucleus-nucleus with respect to proton-nucleus collisions are summarized. In particular, the new data from the WA97 experiment on Ω, Ξ and Λ production in PbPb and p-Pb collisions are presented and discussed.

Strange and multistrange baryon production is expected to be enhanced in heavy ion interactions if a phase transition from hadronic matter to a Quark-Gluon Plasma takes place. The production yields of Λs, Λ s, Ξ−s, and Ξ + s relative to the production of negative particles are presented for sulphur-tungsten interactions at 200 GeV/c per nucleon. These production yields are compared to those produced in proton-tungsten interactions and the enhancements of strange and multistrange baryons and antibaryons are presented.

A, Ξ and Ω yields and transverse mass spectra have been measured in Pb-Pb and p-Pb collisions at 158A GeV/c. The yields in Pb-Pb interactions are presented as a function of the collision centrality and compared with those obtained from p-Pb collisions. Strangeness enhancement is observed which increases with centrality and with the strangeness content of the hyperon.

Enhanced production of strange baryons and anti-baryons at central rapidity in S-W and S-z.sbnd;S with respect to p-A reactions has been reported by the CERN experiments WA85 and WA94. The WA97 experiment is extending such a study to Pb Pb collisions making use of the newly developed silicon pixel detectors. Results on Λ, Ξ − and Ω − production in Pb Pb collisions at 158 A GeV/ c at central rapidity are presented. Transverse mass spectra and particle ratios are presented. Hyperon yields are given as a function of the collision centrality and compared with those obtained from p-Pb collisions using the same experimental setup.

The reaction pp -> pf (pi+pi-pi0) ps has been studied at 450 GeV/c in an experiment designed to search for gluonic states. A spin analysis has been performed and the dPT filter applied. The analysis confirms the previous observation that all undisputed qqbar states are suppressed at small dPT. In addition, a clear difference is observed in the production mechanism for the eta and omega. The reaction pp → p f ( π + π − π 0 ) p s has been studied at 450 GeV/c in an experiment designed to search for gluonic states. A spin analysis has been performed and the dP T filter applied. The analysis confirms the previous observation that all undisputed q q states are suppressed at small dP T . In addition, a clear difference is observed in the production mechanism for the η and ω . The reaction pp -> pf (pi+pi-pi0) ps has been studied at 450 GeV/c in an experiment designed to search for gluonic states. A spin analysis has been performed and the dPT filter applied. The analysis confirms the previous observation that all undisputed qqbar states are suppressed at small dPT. In addition, a clear difference is observed in the production mechanism for the eta and omega.

Charged particle production in central S-S collisions at 200 GeV/c per nucleon has been studied by the WA94 experiment at the CERN-SPS. Particle identification has been provided by the Omega RICH, while a silicon telescope in the Omega spectrometer and an array of MultiWire Proportional Chambers have been used to trace particles through the RICH detector. Production ratios and transverse mass spectra for π±, K± and p( p ) at central rapidity and pT > 1.3 GeV/c are presented.

Photons produced in pi p interactions at 280 GeV/c were detected by reconstructing the e+e- pairs produced via the materialisation of the photons in a 1 mm thick lead sheet placed in front of the MWPCs of the OMEGA spectrometer at CERN. A soft photon signal 7.8 +/- 1.5 times the Q.E.D. inner bremsstrahlung prediction was observed confirming the results of a previous experiment., 11 pages, Latex, 3 Figures plus layout figure

The WA94 collaboration uses the production of strange and anti-strange particles to investigate the properties of hot hadronic matter created in heavy-ion interactions. Λ,\(\bar \Lambda \), Ξ− and\(\bar \Xi ^ + \) particle yields and transverse mass spectra are presented for pS interactions and are compared with those for SS interactions and for the pW and SW interactions of WA85.

Preliminary results from WA97 measurements on Λ, Ξ and Ω production in lead-lead and proton-lead collisions are presented, along with a comparison of WA97 proton-lead data with previous WA85 proton-tungsten results. The ratio Ω/Ξ seems to be enhanced in lead initiated reactions compared to proton initiated reactions.

Strange and multistrange baryon and antibaryon production is a useful probe into the dynamics of the hot hadronic matter created in central heavy ion interactions. Relative production yields and transverse mass spectra are presented and compared for pW and SW interactions.

Central \pipi events produced in pp interactions are studied in terms of correlations between the outgoing protons. It is observed there is more $\rho^{0}$(770) and \fmeson production in reactions where the outgoing protons %fastest and slowest particles in the laboratory frame are on opposite sides of the beam. This effect is not attributable to the trigger or the experimental acceptance, and suggests that the vertices do not factorise.

We present preliminary results about charged particle production in SS collisions at 200 GeV/ c per nucleon, obtained by WA94 experiment at CERN-SPS. The particle identification has been provided by the Omega RICH; a silicon telescope and an array of multiwire proportional chambers (MWPC) have been used to track particles to the RICH detector. Details about particle tracking and identification procedure are also reported.

We study the production of meson resonance atpT≥2 GeV/c inπ− Be interactions at two beam energies (150 and 300 GeV/c). The motivation is to look for the higher twist (HT) production mechanism, expected to exist besides standard hadron production through the fragmentation process of scattered quarks and gluons, the so-called leading twist (LT) mechanism. We show that the φ, K*0 (892) andK*0 (892) are found free from HT effects with a good accuracy, as expected from HT estimates and QCD sum rules. The magnitudes of thef2(1270) andρ0 mesons signals are found larger than expected from the standard Lund (LT) Monte Carlo and from information provided bye+e− annihilation experiments. The possible connection of these excesses with HT physics is discussed. We also report the first evidence for the production off0(975) mesons in hadronic experiments at largepT.

Strange and multistrange baryon and antibaryon production is a useful probe into the dynamics of the hot hadronic matter created in central heavy ion interactions. Relative production yields and transverse mass spectra are presented for Λ, Λ, Ξ− and Ξ+ hyperons produced in central sulphur-tungsten interactions at 200 GeV/c per nucleon.

Recommender systems are becoming increasingly important for businesses because they can help companies offer personalized product recommendations to customers. There have been many acknowledged recognized successes of consumer-oriented recommender systems, particularly in e-commerce. In this work, we describe our experiences building a business-to-business (B2B) recommendation engine that matches company clients to internal company products. The underlying pairing of clients and products is based on co-clustering principles and helps reveal potential future purchases. Unlike most consumer-oriented recommendation systems, our approach takes into account the need for interpretability. We do not only provide a cursory explanation, as offered in most traditional recommender systems. In our approach, the recipient of the generated recommendations are sales and marketing teams; thus, we offer a detailed reasoning in straightforward English that considers multiple aspects regarding why a client may be a suitable match for the particular offering. Finally, we analyze the outcome of a country-wide deployment of the proposed methodology for selected IBM sales teams.

An analysis of the centrally produced π + π − and π + π − π + π − mass spectra from the WA76 and WA91 experiments is presented, which shows that in the π + π − π + π − channel there are two new states, the f 0 (1450) and f 2 (1900). There is another new state in the π + π − channel with M = 1497 ± 30 MeV and Γ = 199 ± 30 MeV, which is compatible with the f 0 (1520) observed by the Crystal Barrel experiment. Another interpretation is discussed, where the 1450 and 1497 GeV structures are explained as being due to an interference effect between the f 0 (1365) and f 0 (1520).

Multi-strange baryon and anti-baryon production is expected to be a useful probe in the search for Quark-Gluon Plasma formation. We present the transverse mass distributions of negative particles, K o s, Λs, Λ s, and Ξ − s produced in sulphurtungsten interactions at 200 GeV/c per nucleon and give the corrected ratios Λ Λ, Ξ − Λ and Ξ − /Λ . We note that our ratio Ξ − / Λ appears large in comparison to that from p p interactions.

We report results on the production of strange baryons/antibaryons with 1, 2, and 3 units of strangeness (Λ, Ξ and Ω) and mesons (K s 0 , K + and K − ) in WA85 experiment at the CERN SPS. This experiment was designed to study the production of strange particles in central SW collisions at 200 GeV/c per nucleon, in the central rapidity region with medium to high p t . We have measured the inverse slopes of the m t distributions of such particles and the production ratios Λ /Λ, Ξ + /Ξ − , Ξ − / Λ , Ξ + / Λ , K s 0 / Λ , K s 0 / Λ , (Ω − + Ω + ) (Ξ − + Ξ + ) and K + K − . Preliminary results on the production ratios Ξ − / Λ and Ξ + / Λ in pW collisions at 200 GeV/c are also presented.

We have performed a search for vector-vector final states centrally produced in the reaction pp→pf(VV)ps at 300 GeV/c using the CERN Ω spectrometer. Evidence is found for ωπ0, ωω, π0π0 and π+π- associated production. No evidence is found for ωϕ production.

Experiment WA91 searches for non-\(q\bar q\) mesons produced in the central region in the reaction pp→pf(X0)ps at 450 GeV/c using the CERN Omega Spectrometer. WA91 is a continuation of the WA76 experiment which has studied this reaction using beams of 85 and 300 GeV/c. Preliminary results from experiment WA91 are presented. In particular the X(1450) and X(1900) observed for the first time in the π+π-π+π- channel of the WA76 experiment at 300 GeV/c are confirmed by the WA91 data.

We study the shape of the invariant mass spectra of several resonances produced atPT≧2.0 GeV/c and observed through two-particle final states, namely thef2(1270),K*(892),\(\bar K*(892)\),K*(1430), and\(\bar K*(1430)\) mesons. The data sample comes from π− Be interactions atPlab=150 GeV/c and 300 GeV/c which have been collected using the OMEGA spectrometer at CERN. We find that although these meson resonances have their masses and widths consistent with the corresponding world average values, their shapes are all subject to the same kind of distortion: their low-mass tail is enhanced while their high-mass tail is sharply cut. This observation indicates that meson resonances produced in the fragmentation of quarks and gluons are distorted by the same damping factor in a way which preserves their masses and lifetimes.

We present the analysis of data samples taken by the WA77 experiment for π- interactions at 300 and 150 GeV/c. The trigger selects a pair of oppositely charged particles withp T ≥2 GeV/c balancing the transverse momentum of a third high-p T track. The primary aim of this experiment was the search for higher-twist production, mainly that of vector mesons. Since there are definite predictions for the polarization of mesons produced in fragmentation and through the higher-twist mechanism, we study the polarization properties of clearly identified mesons, namely the Φ and f2(1270) mesons. The results are compatible with no polarization. This can be interpreted as a production dominantly due to parton fragmentation.

We have extracted from the full WA85 1990 data set a sample of 14ω − + ω − candidates. We describe the selection criteria, and give a measurement of the ω − /ω − ratio at central rapidity and PT > 1.6 GeV/c.

We show that every Banach space $X$ containing an isomorphic copy of $c_0$ has an infinite equilateral set and also that if $X$ has a bounded biorthogonal system of size $\alpha$ then it can be renormed so as to admit an equilateral set of equal size. If $K$ is any compact non metrizable space, then under a certain combinatorial condition on $K$ the Banach space $C(K)$ has an uncountable equilateral set., Comment: to appear in Proc. Am. Math. Soc. (9 pages, no figures)

We have performed a search for vector-vector final states centrally produced in proton proton interactions at 300 GeV/c using the CERN Ω spectrometer. Evidence is found for ωρ0 production in the reactionpp→p f (2π+2π−2π0)p s and for ωω production in the reactionpp→p f (2π+2π−2π0)p s . However no evidence is found for ωo production in the reactionpp→p f (K + K −π+π−π0)p s .

The transverse momentum distributions for\(\rho ^0 (770),f_2 (1270),K*^0 (892),\bar K*^0 (892)\) and ϕ (1020) have been studied in thept region between 2 and 4 GeV/c and central rapidity. The data analysed come from the WA77 experiment at CERN with a 300 GeV/c π− beam incident on a Be target. These distributions are well described by the functionpt−n withn∼8. A sample of simulated events from the Lund Monte Carlo in the same experimental conditions reproduces well the data.

The reactionpp→pf(π+π−γ)ps, where theπ+π−γ system is centrally produced, has been studied at 300 GeV/c. Theπ+π−γ mass spectrum shows evidence for aρ0γ decay mode of theη′ (958) andf1 (1285). The branching ratio (f1(1285)→ηπ+π+)/(f1(1285)→ρ0γ) is found to be 5.0±0.7. No evidence is found for aρ0(770)γ decay mode of theE/f1 (1420) for which an upper limit BR (E/f1(1420)→ρ0γ)

Multi-strange baryon and antibaryon production is expected to be a useful probe in the search for quark-gluon plasma formation. We present the transverse mass distributions of negative particles, Λ' s , Λ ' s and Ξ − ' s produced in sulphur-tungsten interactions at 200 GeV/c per nucleon and give the corrected rations Λ /Λ, Ξ − /Λ and Ξ − / Λ . Our ratio Ξ − / Λ appears to be larger than that from pp interactions.

We have studied the ππ andK\(\bar K\) systems centrally produced in proton proton collisions at 300 GeV/c and π+/p proton collisions at 85 GeV/c using the CERN Ω spectrometer. Clear evidence forS*/fo(975) production is observed. An analysis performed on the π+ π− mass spectrum in the 1.0 GeV region, using a coupled channel formalism, shows that it is possible to describe theS*/fo(975) effect with one single resonance once interference of theS*/fo(975) with theS-wave background is introduced. The resultingS*/fo(975) parameters aremo=979±4MeV,gπ=0.28±0.04,gK=0.56±0.18 corresponding to a pole position on sheet II at (1001±2)−i(36±4) MeV. Evidence is also found for a structure having a mass of 1472±12 MeV and a width of 195±33 MeV.

The reactionpp→pf(ηπ+π−)ps where the ηπ+π− system is centrally produced has been studied at 300 GeV/c incident momentum at the CERN Ω spectrometer. The ηπ± mass spectrum shows a strong δ/a0(980) signal having a mass of 984±4 and Γ=95±14 MeV. The ηπ+π− mass spectrum shows η′ andf1(1285) signals over little background. A spin-parity analysis of the ηπ+π− system shows evidence for aJPC=1++ peak at thef1(1285) mass but no evidence for the pseudoscalar states η(1270) andl/η(1440). No evidence is found for the ηππ decay of theE/f1(1420) meson for which we set an upper limit BR(E/f1(1420)→ηππ)

Production of multi-strange baryons and antibaryons is expected to be a useful indicator in the search for Quark-Gluon Plasma formation. Production of Ξ− and Ξ − has been observed for the first time in ultra-relativistic heavy ion interactions by the WA85 Experiment. We describe the procedure used to select these cascade candidates and show that Ξ− and Ξ − decays can be identified. Preliminary ratios of Ξ/Ξ production in sulphur-tungsten and proton-tungsten interactions are also presented.

The reactionpp→pf(K+K-π+π-)ps, where theK+K− π+π- system is centrally produced, has been studied at 300 GeV/c. TheK*0\(K^{*0} \bar K^{*0} \) final state has been observed and the cross sections for its central production are found to be the same at 300 and 85 GeV/c. TheK*0\(K^{*0} \bar K^{*0} \) final state appears to be produced as a non-resonant threshold enhancement.