1,129 research outputs found

    Individual Fairness in Hindsight

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    Since many critical decisions impacting human lives are increasingly being made by algorithms, it is important to ensure that the treatment of individuals under such algorithms is demonstrably fair under reasonable notions of fairness. One compelling notion proposed in the literature is that of individual fairness (IF), which advocates that similar individuals should be treated similarly (Dwork et al. 2012). Originally proposed for offline decisions, this notion does not, however, account for temporal considerations relevant for online decision-making. In this paper, we extend the notion of IF to account for the time at which a decision is made, in settings where there exists a notion of conduciveness of decisions as perceived by the affected individuals. We introduce two definitions: (i) fairness-across-time (FT) and (ii) fairness-in-hindsight (FH). FT is the simplest temporal extension of IF where treatment of individuals is required to be individually fair relative to the past as well as future, while in FH, we require a one-sided notion of individual fairness that is defined relative to only the past decisions. We show that these two definitions can have drastically different implications in the setting where the principal needs to learn the utility model. Linear regret relative to optimal individually fair decisions is inevitable under FT for non-trivial examples. On the other hand, we design a new algorithm: Cautious Fair Exploration (CaFE), which satisfies FH and achieves sub-linear regret guarantees for a broad range of settings. We characterize lower bounds showing that these guarantees are order-optimal in the worst case. FH can thus be embedded as a primary safeguard against unfair discrimination in algorithmic deployments, without hindering the ability to take good decisions in the long-run

    E3 : Keyphrase based News Event Exploration Engine

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    This paper presents a novel system E3 for extracting keyphrases from news content for the purpose of offering the news audience a broad overview of news events, with especially high content volume. Given an input query, E3 extracts keyphrases and enrich them by tagging, ranking and finding role for frequently associated keyphrases. Also, E3 finds the novelty and activeness of keyphrases using news publication date, to identify the most interesting and informative keyphrases

    Retain Existing Business Process with the 3rd Party Supplier

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    Conveo was XYZ’s partner and announced its intension to disengage from the partnership. XYZ made a decision to change its partner from Conveo to CGX for print and order fulfillment of their marketing materials. XYZ self-accessed the sales tax with Conveo and provided Cenveo a MN direct pay permit so Cenveo had the proper documentation to omit sales tax from the invoices sent to XYZ. The business process described above was intended to be leveraged with the transition to CGX. During the transition of suppliers from Cenveo to CGX, CGX was purchased by RRD, which is also a 3rd party business supplier of XYZ. The existing business process between XYZ and RRD for print materials, warehouse inventory, and order fulfillment services does not utilize the direct pay permit for tax. Since XYZ was not allowed to have two different processes of applying sales tax with a single supplier, there was a need to have a consistent process. A decision was made to discontinue using the MN direct pay permit with RRD. The intent of the project is to implement a standard process for calculating sales tax for the print, order fulfillment, and related services of marketing and verify the results by doing extensive testing using Quality Center Testing includes vendor’s sales tax assessment for all activity completed for XYZ. The objective of the testing is to ensure XYZ’s “approved” business and system requirements have been satisfied through the combination of various application interactions and business processes

    Vacuum growth of N-octylphosphonic acid monolayer for low-voltage organic thin-film transistors

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    This thesis optimizes the vacuum, vapour-phase self-assembly of n-octyl phosphonic acid monolayer. This monolayer is chemisorbed to the aluminium oxide (AIOx) and together they form an ultra-thin gate dielectric in organic thin-film transistors based on pentacene. The electrical measurements of the transistors and the corresponding metal-insulator-metal structures were combined with the characterization of n-octylphosphonic acid monolayers using the atomic force microscopy, water contact angle measurement and Fourier transform infrared spectroscopy. The results show that the properties of the organic monolayer depend on its evaporation rate, growth temperature and the post-growth annealing and affect the performance of the as-fabricated transistors as well as the transistor bias-induced instability.This thesis optimizes the vacuum, vapour-phase self-assembly of n-octyl phosphonic acid monolayer. This monolayer is chemisorbed to the aluminium oxide (AIOx) and together they form an ultra-thin gate dielectric in organic thin-film transistors based on pentacene. The electrical measurements of the transistors and the corresponding metal-insulator-metal structures were combined with the characterization of n-octylphosphonic acid monolayers using the atomic force microscopy, water contact angle measurement and Fourier transform infrared spectroscopy. The results show that the properties of the organic monolayer depend on its evaporation rate, growth temperature and the post-growth annealing and affect the performance of the as-fabricated transistors as well as the transistor bias-induced instability

    Dry growth of n-octylphosphonic acid monolayer for low-voltage organic thin-film transistors

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    Dry method for monolayer deposition of n-octylphosphonic acid (C8PA) on the surface of aluminium oxide (AlOx) is presented. Vacuum thermal evaporation is employed to deposit initial thickness corresponding to several C8PA monolayers, followed by a thermal desorption of the physisorbed C8PA molecules. AlOx functionalized with such C8PA monolayer exhibits leakage current density of ∼10−7 A/cm2 at 3 V, electric breakdown field of ∼6 MV/cm, and a root-mean-square surface roughness of 0.36 nm. The performance of low-voltage pentacene thin-film transistors that implement this dry AlOx/C8PA gate dielectric depends on C8PA desorption time. When the desorption time rises from 25 to 210 min, the field-effect mobility increases from ∼0.02 to ∼0.04 cm2/V s, threshold voltage rises from ∼−1.2 to ∼−1.4 V, sub-threshold slope decreases from ∼120 to ∼80 mV/decade, off-current decreases from ∼5 × 10−12 to ∼1 × 10−12 A, on/off current ratio rises from ∼3.8 × 104 to ∼2.5 × 105, and the transistor hysteresis decreases from 61 to 26 mV. These results collectively support a two stage model of the desorption process where the removal of the physisorbed C8PA molecules is followed by the annealing of the defect sites in the remaining C8PA monolayer

    Optimizing the deposition rate of vacuum-grown n-octylphosphonic acid monolayer for low-voltage thin-film transistors

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    A self-assembled monolayer of n-octylphosphonic acid (C8PA) is prepared from vapor phase in vacuum. C8PA thickness corresponding to several monolayers is deposited on aluminum oxide (AlOx) and subsequently heated to leave a monolayer of chemisorbed molecules. The effect of C8PA deposition rate on a 15-nm-thick, bilayer AlOx/C8PA dielectric and low-voltage p-channel organic thin-film transistors (OTFTs) is studied. The increase in the deposition rate from 0.1 to 7.0 Å/s leads to increase in the field-effect mobility from 0.039 to 0.061 cm2/Vs, while the threshold voltage remains around −1.55 V. At the same time, the off-current is reduced from 2.3 × 10−12 to 1.3 × 10−12A, the subthreshold slope is lowered from 100 to 89 mV/decade and the on/off current ratio is increased from ∼105 to ∼106. The leakage current density of AlOx is reduced from 1 × 10−7 to 4 × 10−8 A/cm2 at 3 V when C8PA monolayer is added on top of it. In addition, pentacene grain size on AlOx/C8PA is larger than that on AlOx. The overall performance of AlOx/C8PA OTFTs is superior to that of AlOx OTFTs

    Insulator superconductor transition on solid inert gas substrates

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    We present observations of the insulator-superconductor transition in ultrathin films of Bi on solid xenon condensed on quartz and on Ge on quartz. The relative permeability ϵr\epsilon_{r} ranges from 1.5 for Xe to 15 for Ge. Though we find screening effects as expected, the I-S transition is robust, and unmodified by the substrate. The resistance separatrix is found to be close to h/4e2h/4e^2 and the crossover thickness close to 25 A˚\AA for all substrates. I-V studies and Aslamazov-Larkin analyses indicate superconductivity is inhomogeneous. The transition is best described in terms of a percolation model.Comment: Submitted to LT23 Proceeding

    Occult Hepatitis B Virus infection in ART-Naive HIV-Infected Patients seen at a Tertiary Care Centre in North India

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    <p>Abstract</p> <p>Background</p> <p>Co-infections of hepatitis B and C viruses are frequent with HIV due to shared routes of transmission. In most of the tertiary care health settings, HIV reactive patients are routinely tested for HBsAg and anti-HCV antibodies to rule out these co-infections. However, using the routine serological markers one can only detect active HBV infection while the occult HBV infection may be missed. There is insufficient data from India on HIV-HBV co-infection and even scarce on occult HBV infection in this group.</p> <p>Methods</p> <p>We estimated the burden of HBV infection in patients who were tested positive for HIV at a tertiary care centre in north India. We also attempted to determine the prevalence and clinical characteristics of occult HBV infection among these treatment-naïve patients and compare their demographic features with other HIV patients. During a period of 6 years between January 2002 to December 2007, 837 HIV positive patients (631 males and 206 females (M: F :: 3.06:1) were tested for serological markers of HBV (HBsAg) and HCV (anti-HCV antibodies) infections in our laboratory. For comparison 1000 apparently healthy, HIV-negative organ donors were also included in the study. Data on demographics, sexual behaviour, medical history, laboratory tests including the serum ALT and CD4 count of these patients were recorded. A sub-group of 53 HBsAg negative samples from HIV positive patients were assessed for anti-HBs, anti-HBc total (IgG+IgM) and HBV-DNA using a highly sensitive qualitative PCR and analysed retrospectively.</p> <p>Results</p> <p>Overall, 7.28% of HIV positive patients showed presence of HBsAg as compared to 1.4% in the HIV negative control group. The prevalence of HBsAg was higher (8.55%) in males than females (3.39%). The study revealed that occult HBV infection with detectable HBV-DNA was prevalent in 24.5% of patients positive for anti-HBc antibodies; being 45.5% in HBsAg negative patients. Most importantly the occult infection was seen in 20.7% patients who were positive for anti-HBs antibodies. However, in none of the seronegative patient HBV-DNA was detected. Five of the nine HBV-DNA positive (55.6%) patients showed raised alanine aminotransferase levels and 66.7% had CD4<sup>+ </sup>T cell counts below 200 cells/cumm.</p> <p>Conclusions</p> <p>High prevalence of HIV-HBV co-infection was found in our patients. A sizeable number of co-infected patients remain undiagnosed, if only conventional serological markers are used. Presence of anti-HBs antibodies was not a reliable surrogate marker to rule out occult HBV infection. The most reliable method to diagnose occult HBV co-infection in HIV seropositive patients is the detection of HBV-DNA.</p
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