692 research outputs found

    High Strength Magnesium Matrix Composites Reinforced with Carbon Nanotube

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    Microscopic Observation of Plastic Deformation of Polycrystalline Aluminum by Laser Scanning Microscope

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    Free surface of polycrystalline metal becomes roughened after plastic deformation. The surface roughening is closely related to the inhomogeneity of polycrystalline metals, that is, to the inhomogeneous plastic deformation of respective grains. In the present study, inhomogeneous deformation on the free surface of polycrystalline aluminum specimen during uniaxial tension is studied. The inhomogeneous deformation of grains in the central area of the free surface of specimen is observed by the laser scanning microscope, while the inhomogeneous deformation perpendicular to the surface is studied by the laser scanning microscope as well as the stylus measuring instrument. It is shown that the surface roughness and the strain of respective grains increase with the applied strain. Discussions are made on the change in the surface roughness, the strain in each grain and the slip-line angles with the applied strain

    Causal relationship between eWOM topics and profit of rural tourism at Japanese Roadside Stations "MICHINOEKI"

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    Affected by urbanization, centralization and the decrease of overall population, Japan has been making efforts to revitalize the rural areas across the country. One particular effort is to increase tourism to these rural areas via regional branding, using local farm products as tourist attractions across Japan. Particularly, a program subsidized by the government called Michinoeki, which stands for 'roadside station', was created 20 years ago and it strives to provide a safe and comfortable space for cultural interaction between road travelers and the local community, as well as offering refreshment, and relevant information to travelers. However, despite its importance in the revitalization of the Japanese economy, studies with newer technologies and methodologies are lacking. Using sales data from establishments in the Kyushu area of Japan, we used Support Vector to classify content from Twitter into relevant topics and studied their causal relationship to the sales for each establishment using LiNGAM, a linear non-gaussian acyclic model built for causal structure analysis, to perform an improved market analysis considering more than just correlation. Under the hypotheses stated by the LiNGAM model, we discovered a positive causal relationship between the number of tweets mentioning those establishments, specially mentioning deserts, a need for better access and traf^ic options, and a potentially untapped customer base in motorcycle biker groups

    Exhaled Breath Marker in Asthma Patients with Gastroesophageal Reflux Disease

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    Prevention of acid is important in gastroesophageal reflex disease (GERD)-related asthma therapy. Proton pump inhibitors (PPI) and H2-receptor blockers have been reported as useful therapies for improving asthma symptoms. GERD prevalence is high in asthma; however, methods for validating GERD existence based on questionnaire, endoscopic examination and 24h-pH monitoring do not directly determine GERD influence on the airway. Exhaled breath condensate analysis is a novel and non-invasive tool for assessing information directly from the airway. Breath collected by cooling can be applied to pH, 8-isoprostane and cytokine analysis in patients with GERD-related asthma, and the pH and 8-isoprostane levels have been shown to reflect the effects of PPI therapy in these patients. Although the analysis of cooled breath has not yet been established in a clinical setting, this method is expected to provide a novel tool for monitoring airway acidification associated with GERD

    Different gastoroesophageal reflux symptoms of middle-aged to elderly asthma and chronic obstructive pulmonary disease (COPD) patients

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    Symptomatic differences and the impact of gastroesophageal reflux disease (GERD) have not been clarified in patients with asthma and chronic obstructive pulmonary disease (COPD). The purpose of this study is to assess the differences of GERD symptoms among asthma, COPD, and disease control patients, and determine the impact of GERD symptoms on exacerbation of asthma or COPD by using a new questionnaire for GERD. A total of 120 subjects underwent assessment with the frequency scale for the symptoms of GERD (FSSG) questionnaire, including 40 age-matched patients in each of the asthma, COPD, and disease control groups. Asthma and control patients had more regurgitation-related symptoms than COPD patients (p<0.05), while COPD patients had more dysmotility-related symptoms than asthma patients (p<0.01) or disease control patients (p<0.01). The most distinctive symptom of asthma patients with GERD was an unusual sensation in the throat, while bloated stomach was the chief symptom of COPD patients with GERD, and these symptoms were associated with disease exacerbations. The presence of GERD diagnosed by the total score of FSSG influences the exacerbation of COPD. GERD symptoms differed between asthma and COPD patients, and the presence of GERD diagnosed by the FSSG influences the exacerbation of COPD

    Crystal Structure of 200 K-Superconducting Phase of Sulfur Hydride System

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    This article reports the experimentally clarified crystal structure of a recently discovered sulfur hydride in high temperature superconducting phase which has the highest critical temperature Tc over 200 K which has been ever reported. For understanding the mechanism of the high superconductivity, the information of its crystal structure is very essential. Herein we have carried out the simultaneous measurements electrical resistance and synchrotron x-ray diffraction under high pressure, and clearly revealed that the hydrogen sulfide, H2S, decomposes to H3S and its crystal structure has body-centered cubic symmetry in the superconducting phase.Comment: 8 pages, 3 figure

    Off-Policy Evaluation of Ranking Policies under Diverse User Behavior

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    Ranking interfaces are everywhere in online platforms. There is thus an ever growing interest in their Off-Policy Evaluation (OPE), aiming towards an accurate performance evaluation of ranking policies using logged data. A de-facto approach for OPE is Inverse Propensity Scoring (IPS), which provides an unbiased and consistent value estimate. However, it becomes extremely inaccurate in the ranking setup due to its high variance under large action spaces. To deal with this problem, previous studies assume either independent or cascade user behavior, resulting in some ranking versions of IPS. While these estimators are somewhat effective in reducing the variance, all existing estimators apply a single universal assumption to every user, causing excessive bias and variance. Therefore, this work explores a far more general formulation where user behavior is diverse and can vary depending on the user context. We show that the resulting estimator, which we call Adaptive IPS (AIPS), can be unbiased under any complex user behavior. Moreover, AIPS achieves the minimum variance among all unbiased estimators based on IPS. We further develop a procedure to identify the appropriate user behavior model to minimize the mean squared error (MSE) of AIPS in a data-driven fashion. Extensive experiments demonstrate that the empirical accuracy improvement can be significant, enabling effective OPE of ranking systems even under diverse user behavior.Comment: KDD2023 Research trac

    Map-guided surgery for atrial fibrillation

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    BackgroundAlthough current surgical procedures result in a high success rate for atrial fibrillation, they are not guided by electrophysiologic findings in individual patients and thus might include unnecessary incisions in some patients or be inappropriate for other patients. We sought to determine whether intraoperative mapping is beneficial for the surgical treatment of atrial fibrillation.MethodsA 256-channel 3-dimensional dynamic mapping system with custom-made epicardial patch electrodes was used to examine the atrial activation during atrial fibrillation and to determine the optimal procedure in 37 patients with continuous and 9 patients with intermittent atrial fibrillation intraoperatively.ResultsSurgical intervention for atrial fibrillation was not indicated in 3 patients in whom the atrial electrograms had a low voltage over a broad area. Concurrent, multiple, and repetitive activations arising from the pulmonary veins or left atrial appendage were observed in all patients. A simple left atrial procedure consisting of pulmonary vein isolation and left atrial incisions without any right atrial incisions was performed in 8 patients in whom the right atrial activation was passive, and all (100%) were cured of atrial fibrillation. The radial procedure was performed in the remaining 35 patients, and 31 (89%) of the patients were cured of atrial fibrillation. In this subset of patients, 10 exhibited reentrant or focal activation in the posterior left atrium between the right and left pulmonary veins and required an additional linear ablation on the posterior left atrium. The total amount of postoperative bleeding after the simple left atrial procedure was significantly less than after the radial procedure (378 ± 135 vs 711 ± 364 mL, P = .03). The right and left atrial transport functions were well preserved after both the radial and simple left atrial procedures.ConclusionIntraoperative mapping facilitates determining the optimal procedure for atrial fibrillation in each patient
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