542 research outputs found

    Key Users and Box Office Analysis in an Interest Based Virtual Community

    Get PDF
    In recent years, with the growth of the Internet technology, the users of virtual community not only play the role of the information receiver but also a very important one to provide information. However, there is large amount of information aggregated daily and therefore information overloading has become a very serious problem. Under this situation, how to find information efficiently is also a very important issue. In this paper, we believe users in a virtual community may affect each other, especially those with high influence who have been called as Key Users. Therefore, we observe the biggest virtual community of movies on the Internet which is named IMDb (The Internet Movie Database). An architecture also has been proposed that combines Social Networks Analysis and the features of IMDb to discover those users who have high influence in the virtual community. We collected 17 months (January 2010 to May 2011) from IMDb including 17 366 users and 243 074 reviews. By applying the method we proposed, there are about 22 key users and 111 reviews were discovered. We also use the box office of the movies to justify our results

    Gender Determination using Fingerprint Features

    Get PDF
    Several previous studies have investigated the gender difference of the fingerprint features. However, regarding to the statistical significance of such differences, inconsistent results have been obtained. To resolve this problem and to develop a method for gender determination, this work proposes and tests three fingertip features for gender determination. Fingerprints were obtained from 115 normal healthy adults comprised of 57 male and 58 female volunteers. All persons were born in Taiwan and were of Han nationality. The age range was18-35 years. The features of this study are ridge count, ridge density, and finger size, all three of which can easily be determined by counting and calculation. Experimental results show that the tested ridge density features alone are not very effective for gender determination. However, the proposed ridge count and finger size features of left little fingers are useful, achieving a classification accuracy of 75% (P-valu

    Light scattering properties beyond weak-field excitation in a few-atom system

    Full text link
    In the study of optical properties of large atomic system, a weak laser driving is often assumed to simplify the system dynamics by linearly coupled equations. Here we investigate the light scattering properties of atomic ensembles beyond weak-field excitation through cumulant expansion method. By progressively incorporating higher-order correlations into the steady-state equations, an enhanced accuracy can be achieved in comparison to the exact solutions from solving a full density matrix. Our analysis reveals that, in the regime of weak dipole-dipole interaction (DDI), the first-order expansion yields satisfactory predictions for optical depth, while denser atomic configurations necessitate consideration of higher-order correlations. As the intensity of incident light increases, atom saturation effects become noticeable, giving rise to significant changes of light transparency, energy shift, and decay rate. This saturation phenomenon extends to subradiant atom arrays even under weak driving conditions, leading to substantial deviations from the linear model. Our findings demonstrate the potential of mean-field models as good extensions to linear models as it balances both accuracy and computational complexity, which can be an effective tool for probing optical properties in large atom systems. However, the crucial role of higher-order cumulants in large atom systems under finite laser field excitations remains unclear since it is challenging theoretically owing to the exponentially-increasing Hilbert space in such light-matter interacting systems.Comment: 4 figure

    Gravity Waves from Quantum Stress Tensor Fluctuations in Inflation

    Full text link
    We consider the effects of the quantum stress tensor fluctuations of a conformal field in generating gravity waves in inflationary models. We find a non-scale invariant, non-Gaussian contribution which depends upon the total expansion factor between an initial time and the end of inflation. This spectrum of gravity wave perturbations is an illustration of a negative power spectrum, which is possible in quantum field theory. We discuss possible choices for the initial conditions. If the initial time is taken to be sufficiently early, the fluctuating gravity waves are potentially observable both in the CMB radiation and in gravity wave detectors, and could offer a probe of transplanckian physics. The fact that they have not yet been observed might be used to constrain the duration and energy scale of inflation.Comment: 17 -pages, no figure

    Effects of nerve-sparing procedures on surgical margins after robot-assisted radical prostatectomy

    Get PDF
    BACKGROUND: Nerve-sparing (NS) techniques could potentially increase positive surgical margins (PSM) after robot-assisted radical prostatectomy (RARP). Nevertheless, the available studies have revealed ambiguous results among distinct groups. This study purposed to clarify the details of NS techniques to accurately estimate their influence on margin status. METHODS: We studied RARPs performed by one surgeon from 2010 to 2018. Surgical margins were evaluated by the laterality and levels of NS techniques in site-specific prostate lobes. The multivariable analysis evaluated the effects of nerve-sparing procedures, combined with other covariate factors, on margin status. RESULTS: Overall, four hundred nineteen RARPs involving 838 prostate lobes were analyzed. Notably, 181 patients (43.4%) had pT2-stage, and 236 (56.6%) had pT3-stage cancer. The PSM rates for patients who underwent unilateral, bilateral, and non NS procedures were 30.3%, 28.8%, and 50%, respectively (p = 0.233) or in stratification by pT2 (p = 0.584) and pT3 (p = 0.116) stage. The posterolateral PSM rates among site-specific prostate lobes were 10.9%, 22.4%, and 18.9% for complete, partial, and non NS techniques, respectively (p = 0.001). The partial NS group revealed a significant increase in PSM rate compared with the complete NS (OR 2.187, 95% CI 1.19-4.03) and non NS (OR 2.237, 95% CI 1.01-4.93) groups in site-specific prostate lobes. CONCLUSION: Partial NS procedures have a potential risk of increasing the PSM rate than complete and non NS procedures do. Therefore, correct case selection is required before performing partial NS techniques

    Myopia progression after cessation of atropine in children: a systematic review and meta-analysis

    Get PDF
    Purpose: To comprehensively assess rebound effects by comparing myopia progression during atropine treatment and after discontinuation.Methods: A systematic search of PubMed, EMBASE, Cochrane CENTRAL, and ClinicalTrials.gov was conducted up to 20 September 2023, using the keywords “myopia," “rebound,” and “discontinue." Language restrictions were not applied, and reference lists were scrutinized for relevant studies. Our study selection criteria focused on randomized control trials and interventional studies involving children with myopia, specifically those treated with atropine or combination therapies for a minimum of 6 months, followed by a cessation period of at least 1 month. The analysis centered on reporting annual rates of myopia progression, considering changes in spherical equivalent (SE) or axial length (AL). Data extraction was performed by three independent reviewers, and heterogeneity was assessed using I2 statistics. A random-effects model was applied, and effect sizes were determined through weighted mean differences with 95% confidence intervals Our primary outcome was the evaluation of rebound effects on spherical equivalent or axial length. Subgroup analyses were conducted based on cessation and treatment durations, dosage levels, age, and baseline SE to provide a nuanced understanding of the data.Results: The analysis included 13 studies involving 2060 children. Rebound effects on SE were significantly higher at 6 months (WMD, 0.926 D/y; 95%CI, 0.288–1.563 D/y; p = .004) compared to 12 months (WMD, 0.268 D/y; 95%CI, 0.077–0.460 D/y; p = .006) after discontinuation of atropine. AL showed similar trends, with higher rebound effects at 6 months (WMD, 0.328 mm/y; 95%CI, 0.165–0.492 mm/y; p < .001) compared to 12 months (WMD, 0.121 mm/y; 95%CI, 0.02–0.217 mm/y; p = .014). Sensitivity analyses confirmed consistent results. Shorter treatment durations, younger age, and higher baseline SE levels were associated with more pronounced rebound effects. Transitioning or stepwise cessation still caused rebound effects but combining optical therapy with atropine seemed to prevent the rebound effects.Conclusion: Our meta-analysis highlights the temporal and dose-dependent rebound effects after discontinuing atropine. Individuals with shorter treatment durations, younger age, and higher baseline SE tend to experience more significant rebound effects. Further research on the rebound effect is warranted.Systematic Review Registration: [https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=463093], identifier [registration number

    Association Between Platelet Count and Components of Metabolic Syndrome in Geriatric Taiwanese Women

    Get PDF
    SummaryBackgroundThe growing elderly population in Taiwan, as in many other countries, has resulted in increased importance of the metabolic syndrome (MetS). Although it has been reported in different age groups, the relationship between platelets and MetS remains unknown in geriatric patients.Patients and MethodsWe enrolled 1460 women >65 years old. Women with a known history of diabetes, hyperlipidemia or hypertension or those taking medication for these conditions were all excluded. The women were further divided into quartiles arbitrarily according to platelet count (PC) (PC1–PC4, lowest to highest accordingly).ResultsAmong the MetS components, body mass index (BMI), total cholesterol, low-density lipoprotein cholesterol (LDL-C) and log transformation triglyceride (Log TG) were all significantly higher in the PC4 group (p < 0.05), and they were also positively correlated with PC. However, in multiple regression, BMI became nonsignificant. Both LDL-C and Log TG were the only two factors that remained positively and independently correlated with PC. Compared to PC1, all the other three groups had significantly higher odds ratios for having MetS (2.013, 1.473–2.751; 1.486, 1.081–2.042; 1.537, 1.117–2.114; odds ratios and 95% confidence intervals for PC4, PC3 and PC2, respectively).ConclusionElderly women with MetS had higher PC. Among the five components, TG was positively correlated with PC. There was a positive correlation between PC and LDL-C but not high-density lipoprotein cholesterol. The importance of both lipids might be re-evaluated in the future in older women
    • …
    corecore