Machine learning for outlier detection in medical imaging

Outlier detection is an important problem with diverse practical applications. In medical imaging, there are many diagnostic tasks that can be framed as outlier detection. Since pathologies can manifest in so many different ways, the goal is typically to learn from normal, healthy data and identify any deviations. Unfortunately, many outliers in the medical domain can be subtle and specific, making them difficult to detect without labelled examples. This thesis analyzes some of the nuances of medical data and the value of labels in this context. It goes on to propose several strategies for unsupervised learning. More specifically, these methods are designed to learn discriminative features from data of a single class. One approach uses divergent search to continually find different ways to partition the data and thereby accumulates a repertoire of features. The other proposed methods are based on a self-supervised task that distorts normal data to form a contrasting class. A network can then be trained to localize the irregularities and estimate the degree of foreign interference. This basic technique is further enhanced using advanced image editing to create more natural irregularities. Lastly, the same self-supervised task is repurposed for few-shot learning to create a framework for adaptive outlier detection. These proposed methods are able to outperform conventional strategies across a range of datasets including brain MRI, abdominal CT, chest X-ray, and fetal ultrasound data. In particular, these methods excel at detecting more subtle irregularities. This complements existing methods and aims to maximize benefit to clinicians by detecting fine-grained anomalies that can otherwise require intense scrutiny. Note that all approaches to outlier detection must accept some assumptions; these will affect which types of outliers can be detected. As such, these methods aim for broad generalization within the most medically relevant categories. Ultimately, the hope is to support clinicians and to focus their attention and efforts on the data that warrants further analysis.Open Acces

A FURTHER EXAMINATION OF THE INTERGROUP SENSITIVITY EFFECT: THE MODERATING ROLE OF SOCIAL EXCLUSION, POWER, AND CATEGORY DIFFERENTIATION

Master'sMASTER OF SOCIAL SCIENCE

A Methodology for Cell Merging Circuit Transformation on Post-placement High Speed Design

This paper proposes a localize circuit transformation algorithm to further optimize the post-placement netlist in order to improve the overall timing of a design. The proposed algorithm reduces the total cell delay and net delay of timing violation paths by replacing a small group of cells (form up by two to three cells) that are placed close to each other with a functional equivalent standard cell available in the technology library. The algorithm has been implemented and applied to a number of optimized postplacement netlists which have went through conventional post-placement circuit transformation optimization processes such as gate relocation, cell re-sizing, repeater insertion and cell replication. The experimental results show that on average, this algorithm is able to further improve the timing of the optimized post-placement netlist by 27.75%, while keeping the design area increase by 0.2%

Nitrogen-induced metabolic changes and molecular determinants of carbon allocation in Dunaliella tertiolecta

10.1038/srep37235Scientific Reports61-1

Dynamics of country image: evidence from Malaysia

Purpose – Previous research has posited country image to operate at two levels: the country’s macro image, based on general politico-economic descriptors of the country, and the country’s micro image, based on perceptions of products from the country. The purpose of this paper is to further explore this premise in a practical study, using a psychometric assessment of macro and micro country images by ascertaining the nature of differences in macro and micro images of leading exporters, the USA and China, for consumers in Malaysia, a top import destination of US and Chinese goods; the images of Malaysian goods were similarly assessed. Design/methodology/approach – The study used a systematic sample, with questionnaires distributed to adult respondents using a street intercept. Interviewers asked every other passer-by to fill out a questionnaire, and stood in close proximity to address any questions from respondents. The study hypothesized that there is a significant difference between country macro and micro image, respectively for the USA, China and Malaysia, and that there is significant relationship between country macro image and country micro image in each country, respectively, USA, China and Malaysia. Findings – The study found support for the reliability of existing country micro and macro image measures, and further refined them for increased validity. The study compared between the countries and found significant differences on both macro and micro dimensions of country image. The US scored highest on technological research, high quality products, standards of living, labor costs, welfare system, industrialization, civilian government, development, literacy, free-market system and democracy, followed by China on technological research, industrialization, development and free-market system, with Malaysia scoring higher on product quality, labor costs, welfare system, civilian government is civilian/non-military, literacy, free-market system and democracy. Research limitations/implications – A broader study of countries that share geopolitical and cultural similarities might offer additional insights into country macro and micro image. Practical implications – The study cautions marketers to assess the acceptance of their products in the context of their country’s macro and micro image perceptions in target markets, and steer those perceptions in a manner that would be beneficial to their marketing efforts. Originality/value – The conceptualization of the macro and micro aspects of country image has been one of the less studied dimensions of country image. This study is the first to address these dimensions from an emerging-market perspective, suggesting that, at the macro level, country perceptions regarding technology, economy, and politics contribute to an overall impression of the country, which would then influence the desirability of its products originating there. For the micro country image, products from countries perceived as innovative, excelling in product design, and producing prestigious products, are likely to be perceived as desirable

Numerical study on the coupled vibration characteristics of dual-rotors system with little rotation speed difference

In view of statically indeterminate structures of the decanter centrifuge, an iteration calculation model of nonlinear bearing stiffness is built innovatively. Based on gear meshing stiffness, material and lubricant film damping, coupled dual-rotors vibration model of screw-differential mechanism-bowl is constructed using solid elements. Applying ANSYS modal analysis, critical speeds along with vibration modes of dual-rotors and single-rotor are simulated, and the impacts of the differential mechanism and single-rotor modal on dual-rotors modal are obtained. Built on the harmonic response analysis, the results indicate that the system responses differently for the different rotors by manipulating the dynamic responses of the centrifuge under single rotor unbalance excitation. On the basis of transient structural analysis, beat vibration characteristics of dual-rotors system with little rotation speed difference are obtained, and a conclusion of the system responses separately for the unbalance mass of different rotors at a low rotating speed is acquired. The models and methods adopted in simulation are proved to be reasonable and feasible by experiment. The results have certain significance for the design and the dynamic balancing technique of the decanter centrifuge

A METHOD AND A CONNECTING DEVICE FOR ASSOCIATING USERS AND PHILANTHROPIC ENTITIES

The present disclosure relates to a method and a connecting device for associating users and philanthropic entities to help in community movement. In the present disclosure, initially a connecting device 103 may receive a request from an authorization entity to connect to a philanthropic entity 105. The authorization entity may send the request to the connecting device 103 when the user device 101 initiates a transaction with a merchant. The authorization entity may determine if the user device 101 is enrolled in the charity program. Further, the connecting device 103 may send a request to retrieve the event data associated with the charity program to philanthropic entity 105. The connecting device 103 may further transmit the retrieved event data associated with the charity program to the user device 101. Finally, the connecting device 103 triggers the contribution as charity to the philanthropic entity 105 based on the received response

Prognostic significance of hemoglobin A1c level in patients hospitalized with coronary artery disease. A systematic review and meta-analysis

<p>Abstract</p> <p>Background</p> <p>The prognostic value of hemoglobin A1c (HbA1c) in coronary artery disease (CAD) remains controversial. Herein, we conducted a systematic review to quantify the association between elevated HbA1c levels and all-cause mortality among patients hospitalized with CAD.</p> <p>Methods</p> <p>A systematic search of electronic databases (PubMed, EMBASE, OVID, Web of Science, The Cochrane Library) for studies published from 1970 to May 2011 was performed. Cohort, case-control studies, and randomized controlled trials that examined the effect of HbA1c on all-cause mortality were included.</p> <p>Results</p> <p>Twenty studies met final inclusion criteria (total n = 13, 224). From the pooled analyses, elevated HbA1c level was significantly associated with increased short-term (OR 2.32, 95% CI, 1.61 to 3.35) and long-term (OR 1.54, 95% CI, 1.23 to 1.94) mortality risk. Subgroup analyses suggested elevated HbA1c level predicted higher mortality risk in patients without diabetes (OR 1.84, 95% CI, 1.51 to 2.24). In contrast, in patients with diabetes, elevated HbA1c level was not associated with increased risk of mortality (OR 0.95, 95% CI, 0.70 to 1.28). In a risk-adjusted sensitivity analyses, elevated HbA1c was also associated with a significantly high risk of adjusted mortality in patients without diabetes (adjusted OR 1.49, 95% CI, 1.24 to 1.79), but had a borderline effect in patients with diabetes (adjusted OR 1.05, 95% CI, 1.00 to 1.11).</p> <p>Conclusions</p> <p>Our findings demonstrate that elevated HbA1c level is an independent risk factor for mortality in CAD patients without diabetes, but not in patients with established diabetes. Prospective studies should further investigate whether glycemic control might improve outcomes in CAD patients without previously diagnosed diabetes.</p

The effects of customer personality traits on the display of positive emotions

Academy of Management Journal472287-29