Broken Time Reversal Symmetry and Superconducting States in the Cuprates

Recently, Kaminski et al. have reported that time reversal symmetry is broken in the pseudogap phase in the high temperature superconducting material Bi_2Sr_2CaCu_2O_{2+\delta} (Bi-2212). Here we examine the role of translationally invariant broken time reversal states on d_{x^2-y^2} superconductors. In particular, we determine the change in the superconducting order parameter structure. We find that the broken time reversal pseudogap state that is consistent with the experiment of Kaminski et al., gives rise to a novel mixed singlet-triplet pairing d+ip phase. This d+ip state is shown to give rise to a helical superconducting phase. Consequences of this d+ip state on Josephson experiments are discussed.Comment: 5 pages, 1 figur

Development of automated dynamic bidding agents for final price prediction in online auctions

University of Technology, Sydney. Faculty of Engineering and Information Technology.Online auctions have emerged as a well-recognised paradigm of item exchange over the past few years. In these environments, software agents are being used increasingly and promisingly to bid on or trade goods. This thesis presents an automated dynamic bidding agent framework that makes use of machine learning techniques to forecast bid amounts in simultaneous auctions of the same or similar items. The availability of numerous auctions of similar items complicates the situation of bidders who wish to choose the auction where their participation will give maximum surplus. These bidders also face a perpetual dilemma about how to predict an item’s bargain price. Further, the diverse price dynamics of auctions for the same or similar items affect both the choice of auction and the valuation of the auctioned items. There is, thus, a critical need to characterise auctions based on their price dynamics before selecting one to compete in and assessing the true value of the auctioned items. The main contributions of this thesis are its development of: (i) an automated dynamic bidding agent framework, (ii) an initial price estimation methodology for choosing an auction and assessing the value of auctioned goods, (iii) a final price prediction methodology that designs bidding strategies for buyers with different bidding behaviours and (iv) a simulated electronic marketplace for implementing and evaluating the performance of bidding agents. The automated dynamic bidding agent (ADBA) framework selects an auction to participate in and predicts its final price in two phases: the first gives an initial estimation and the second phase delivers a final price prediction. The methodology for initial price estimation finds an auction to compete in and assesses the value of the auctioned item using data mining techniques. It handles the problem of diverse price dynamics in auctions for the same or similar items, using a clustering-based bid mapping and selection approach to locate the auction where participation would give maximum surplus. The value of the item is assessed with parametric and non-parametric machine learning approaches to predict the auction’s closing price. The proposed approach is validated using real online auction datasets. These results demonstrate that this clustering-based price prediction approach outperforms existing methodologies in terms of prediction accuracy. This thesis also introduces a methodology for final price estimation which designs bidding strategies to address buyers’ different bidding behaviours. This draws on two approaches: negotiation decision functions and fuzzy reasoning techniques. The bidding strategies are designed based on the bidder's own attitude to win the auction and the behaviour of rival bidders. A simulated electronic marketplace is implemented and developed using Java Agent DEvelopment Framework (JADE). The marketplace is also used to demonstrate the performance of the bidding strategies. The outcomes for heterogeneous and homogeneous bidders are measured separately in a wide variety of test environments subject to different auction settings and bidding restrictions. The results show that ADBA agents who follow this study’s bidding strategies outperform other existing agents in most settings in terms of their success rate and expected utility

Social access: role of digital media in social relations of young people with disabilities

Digital media have enabled people with disabilities (PWDs) to connect with each other, but online relations and gaming have been found escapist. We propose the analytical lens of social access to examine how the role of digital media in PWDs’ social relations is shaped by (i) affordances of digital media, (ii) mixedness of relations, and (iii) interaction of online and offline worlds. This paper presents an ethnographic study in a school for young PWDs and highlights two observations. First, visual profiles on social media platforms could aggravate the social exclusion of young PWDs online and offline, marked by intra-disability and intersectional differences. Second, the co-presence afforded by digital media enabled young PWDs to resort to digital interactions in unwelcoming offline environments without changing the latter. Social access underlines the importance of studying how digital media interweave with offline social relations and inequalities, rarely altering but sometimes augmenting and ameliorating them

Access to Justice For Women: India's Response to Sexual Violence in Conflict and Social Upheaval

A 2014 report by the Special Rapporteur on Violence Against Women on gender-based crimes describes the female experience in India as consisting of a "continuum of violence...from the 'womb to the tomb.'" According to Indian government data, a woman is raped in the country approximately every twenty minutes. Women and girls are especially vulnerable to sexual violence during armed conflict and mass violence. Indeed, gender-based crime is a common feature of the armed conflict and mass violence that has marred India since independence.This report examines emblematic case examples from conflict zones and incidents of mass violence to understand how the Indian State responds to sexual violence against women and girls in these contexts. The goal of this report is to analyze the efforts of women victims of sexual violence and their allies to access justice in these contexts and to identify emblematic ways the Indian legal system succeeded or failed to provide effective redress

Ultrasonographic evaluation of antenatal umbilical cord coiling index (aUCI) in second trimester of gestation and pregnancy outcome

Background: To evaluate the role of antenatal umbilical cord coiling index (aUCI) obtained during routine second trimester ultrasound as a predictor of perinatal outcome.Methods: Fetal ultrasound of 100 pregnant women was done between 18-24 weeks of gestation. Antenatal UCI was calculated as a reciprocal value of the distance between a pair of coils. Patients were followed up till delivery for perinatal outcome. UCI was correlated with: (1) gestational age (2) mode of delivery, (3) presence of meconium-stained amniotic fluid, (4) APGAR scores and (5) birth weight.Results: aUCI was categorized as hypocoiled, normocoiled or hypercoiled. Hypocoiled cord was associated with LBW (1%), preterm delivery (1%) while hypercoiled cord was associated with LBW (4%). No statistical difference was found for birth weight, gestational age, APGAR scores and MSAF between the groups with normal and abnormal aUCI.Conclusions: In present study, no association was found between abnormal aUCI with higher prevalence of interventional delivery, presence of MSAF, preterm and LBW. Therefore, more specific parameters need to be developed as promising prognostic marker for predicting adverse perinatal outcome and further studies are needed to test this hypothesis