1,326 research outputs found

    Classification with class noises through probabilistic sampling

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    © 2017 Accurately labeling training data plays a critical role in various supervised learning tasks. Now a wide range of algorithms have been developed to identify and remove mislabeled data as labeling in practical applications might be erroneous due to various reasons. In essence, these algorithms adopt the strategy of one-zero sampling (OSAM), wherein a sample will be selected and retained only if it is recognized as clean. There are two types of errors in OSAM: identifying a clean sample as mislabeled and discarding it, or identifying a mislabeled sample as clean and retaining it. These errors could lead to poor classification performance. To improve classification accuracy, this paper proposes a novel probabilistic sampling (PSAM) scheme. In PSAM, a cleaner sample has more chance to be selected. The degree of cleanliness is measured by the confidence on the label. To accurately estimate the confidence value, a probabilistic multiple voting idea is proposed which is able to assign a high confidence value to a clean sample and a low confidence value to a mislabeled sample. Finally, we demonstrate that PSAM could effectively improve the classification accuracy over existing OSAM methods

    A novel CYP1A1 gene polymorphism and the risk of head and neck cancer in Pakistani population

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    Several polymorphisms in the CYP1A1 locus have been identified and their genotypes appear to exhibit population frequencies that depend on ethnicity. In this study, we assessed the role of CYP1A1 genotype in 388 head and neck cancer patients in Pakistani population via a case-control study. Polymerase chain reaction (PCR) and single stranded conformational polymorphism assays were used. Most of the patients (51%) enrolled for the study, were from the age group of 40 to 60 years (±16.59). Mean age of the cancer patients involved in the study was 48 ± 16.59 years. Statistical analysis has shown that, tobacco users have more chances of head and neck cancer (P < 0.05) than non tobacco users, whereas male to female ratio is 1:1 (P > 0.05). Jobless persons are more prone to head and neck cancer (P < 0.01) compared with employers and housewives. After the genetic analysis, it was found that no already reported variants of CYP1A1 gene were found in Pakistani population. A novel mutation in CYP1A1 gene at exon 2 in 21 patients (P < 0.001, Odd Ratio (OR) = 9.4 and 95% confidence interval (CI) 1.3 to 70.8) has been found with a serine formation instead of tyrosine at amino acid 110. The patients showing this mutation have the mean age of 51.75 (±15.7). Therefore, mutation in CYP1A1 gene may be one of several factors that increase the chance of developing head and neck cancer.Key words: Cytochrome P450 1A1 gene (CYP1A1), head and neck cancer (HNC), mutation, novel polymorphism, Pakistani population

    Cost-sensitive elimination of mislabeled training data

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    © 2017 Elsevier Inc. Accurately labeling training data plays a critical role in various supervised learning tasks. Since labeling in practical applications might be erroneous due to various reasons, a wide range of algorithms have been developed to eliminate mislabeled data. These algorithms may make the following two types of errors: identifying a noise-free data as mislabeled, or identifying a mislabeled data as noise free. The effects of these errors may generate different costs, depending on the training datasets and applications. However, the cost variations are usually ignored thus existing works are not optimal regarding costs. In this work, the novel problem of cost-sensitive mislabeled data filtering is studied. By wrapping a cost-minimizing procedure, we propose the prototype cost-sensitive ensemble learning based mislabeled data filtering algorithm, named CSENF. Based on CSENF, we further propose two novel algorithms: the cost-sensitive repeated majority filtering algorithm CSRMF and cost-sensitive repeated consensus filtering algorithm CSRCF. Compared to CSENF, these two algorithms could estimate the mislabeling probability of each training data more confidently. Therefore, they produce less cost compared to CSENF and cost-blind mislabeling filters. Empirical and theoretical evaluations on a set of benchmark datasets illustrate the superior performance of the proposed methods

    Emotion classification and crowd source sensing; a lexicon based approach

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    In today's world, social media provides a valuable platform for conveying expressions, thoughts, point-of-views, and communication between people, from diverse walks of life. There are currently approximately 2.62 billion active users' social networks, and this is expected to exceed 3 billion users by 2021. Social networks used to share ideas and information, allowing interaction across communities, organizations, and so forth. Recent studies have found that the typical individual uses these platforms between 2 and 3 h a day. This creates a vast and rich source of data that can play a critical role in decision-making for companies, political campaigns, and administrative management and welfare. Twitter is one of the important players in the social network arena. Every scale of companies, celebrities, different types of organizations, and leaders use Twitter as an instrument for communicating and engaging with their followers. In this paper, we build upon the idea that Twitter data can be analyzed for crowd source sensing and decision-making. In this paper, a new framework is presented that uses Twitter data and performs crowd source sensing. For the proposed framework, real-time data are obtained and then analyzed for emotion classification using a lexicon-based approach. Previous work has found that weather, understandably, has an impact on mood, and we consider these effects on crowd mood. For the experiments, weather data are collected through an application-programming-interface in R and the impact of weather on human sentiments is analyzed. Visualizations of the data are presented and their usefulness for policy/decision makers in different applications is discussed

    \mu-\tau Symmetry and Maximal CP Violation

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    We argue the possibility that a real part of a flavor neutrino mass matrix only respects a mu-tau symmetry. This possibility is shown to be extended to more general case with a phase parameter \theta, where the mu-tau symmetric part has a phase of \theta/2. This texture shows maximal CP violation and no Majorana CP violation.Comment: 5 pages, version to appear in Phys. Lett.

    Determination of Neutrino Mass Texture for Maximal CP Violation

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    We show a general form of neutrino mass matrix (M), whose matrix elements are denoted by M_{ij} (i.j=e, mu, tau) as flavor neutrino masses, that induces maximal CP violation as well as maximal atmospheric neutrino mixing. The masses of M_{mu mu}, M_{tau tau} and M_{mu tau}+sigma M_{ee} (sigma =\pm 1) turn out to be completely determined by M_{e mu} and M_{e tau} for given mixing angles. The appearance of CP violation is found to originate from the interference between the mu-tau symmetric part of M and its breaking part. If |M_{e mu}|=|M_{e tau}|, giving either M_{e mu}=-sigma e^{i theta} M_{e tau} or M_{e mu}=-sigma e^{i theta}M*_{e tau} with a phase parameter theta, is further imposed, we find that |M_{mu mu}|=|M_{tau tau}|is also satisfied. These two constraints can be regarded as an extended version of the constraints in the mu-tau symmetric texture given by M_{e mu}=-sigma M_{e tau} and M_{mu mu}=M_{tau tau}. Majorana CP violation becomes active if arg(M_{mu tau})\neq arg(M_{e mu})+theta/2 for M_{e mu}=-sigma e^{i theta} M_{e tau} and if arg(M_{mu tau})\neq theta/2 for M_{e mu}=-sigma e^{i theta} M*_{e tau}.Comment: 10 pages, RevTex, typos corrected, minor clarifications added in Sec.3 and Sec.4, version to appear in Nucl. Phys.

    Modified Zee mass matrix with zero-sum condition

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    We modify the Zee mass matrix by adding a real one parameter perturbation which is purely diagonal and trace-less. We show that in this way we can explain both solar and atmospheric neutrino oscillation data. There is a correlation between the deviation from strict maximality of Uμ3=1/2|U_{\mu 3}|= 1/\sqrt{2}, with the emergence of a small but non-zero Ue3U_{e3}. We calculate how big a value can Ue3U_{e3} get when we restrict ourselves within the allowed regions of solar and atmospheric neutrino masses and mixing angles. We also discuss the impact of a S2S_2 permutation symmetry on our mass matrix and show how a small Ue30U_{e3} \ne 0 can emerge when this S2S_2 permutation symmetry between the second and the third generation is broken.Comment: Version to appear in Physics Letters B. (17 pages

    CP Violation and Neutrino Oscillations

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    We review the basic mechanisms of neutrino mass generation and the corresponding structure of the lepton mixing matrix. We summarize the status of three-neutrino oscillation parameters as determined from current observations, using state-of-the-art solar and atmospheric neutrino fluxes, as well as latest experimental data as of September 2007. We also comment on recent attempts to account for these results and to understand flavour from first principles. We discuss extensively the prospects for probing the strength of CP violation in two near term accelerator neutrino oscillation experiments, T2K and NOvA, as well as possible extensions such as T2KK and a second large off-axis detector near the NOvA detector. We also briefly discuss the possibility of probing the effect of Majorana phases in future neutrinoless double beta decay searches and discuss other implications of leptonic CP violation such as leptogenesis. Finally we comment on the issue of robustness of the current oscillation interpretation and possible ways of probing for non-standard neutrino interactions in precision oscillation studies.Comment: 78 pages, 46 figures, minor misprint corrections, a few new references and an acknowledgement to a funding agency. Review to be published in Prog. Part. Nucl. Phy

    A Novel Approach to Policy Development under Disruptive Circumstances using Situation Awareness and Scenario Planning in Higher Education

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    This paper focuses on policy development in a Higher Education context and provides a model for ensuring sustainable educational practice in TNE partnerships under disruptive situations. The focal point of policy initiation and development was the Covid-19 virus outbreak in China and the ensuing impact on program delivery and assessment. The development takes a novel approach by applying a combination of commercial scenario planning and crisis management techniques to create a coherent and prescriptive educational policy for staff operating in a Transnational Education (TNE) partnership based on the fly-in, fly-out (FIFO) faculty model. It demonstrates the application of these management tools and describes how, through careful analysis and planning, disruption to student learning, teaching and assessment can be minimized

    Inguinal lymph node metastases from a testicular seminoma: a case report and a review of the literature

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    <p>Abstract</p> <p>Introduction</p> <p>We report the case of a true hermaphrodite with testicular seminoma with resulting metastases to the inguinal lymph nodes eight months after radical orchidectomy. This is an unusual presentation of testicular cancer and, to the best of our knowledge, the first report of this kind in the literature.</p> <p>Case presentation</p> <p>A 45-year-old Caucasian true hermaphrodite, raised as a male, developed a testicular seminoma. He had undergone a left orchidopexy at the age of 10 for undescended testes. Metastases from testicular tumors to inguinal lymph nodes are a rare occurrence. It has been suggested that previous inguinal or scrotal surgery may alter the pattern of nodal metastasis of testicular cancer. We review the literature to evaluate the incidence of inguinal lymph node involvement in early stage testicular cancer and discuss possible routes of metastases to this unusual site. We also discuss the management of the inguinal lymph nodes in patients with testicular tumors and a previous history of inguinal or scrotal surgery, as this remains controversial.</p> <p>Conclusion</p> <p>Inguinal lymph node metastases from testicular cancer are rare. A history of inguinal or scrotal surgery may predispose involvement of the inguinal nodes. During radical inguinal orchidectomy, the surgeon should be careful to minimize the handling of the testis and ensure high ligation of the spermatic cord up to the internal inguinal ring to reduce the risk of inguinal lymph node metastasis.</p
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