Individual Fairness in Hindsight

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

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

An Impact Analysis of Demonetization on Key Sectors of the Indian Economy

Demonetization has certainly created a stir in the Indian financial market and the Indian economy at large, in terms of its subsequent impact of reduced lending rates, reduced inflation rates, increase in CASA, affordable Real Estate prices, a move towards a cashless society which also imbibes accountability of transactions thus reducing black money laundering, affordable oil and travel costs and many more. As many economists and industrialists have pointed out, there may be an initial dip in sales, business and hence the seemingly overall growth, but in the long-run, the demonetization drive of 2016 will have a definite positive and a lasting effect. DOI: 10.5281/zenodo.346483

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

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

Structural changes in vapour-assembled n-octylphosphonic acid monolayer with post-deposition annealing : correlation with bias-induced transistor instability

We report on the link between the structure of n-octylphosphonic acid (C8PA) monolayer implemented in low-voltage organic thin-film transistors (OTFTs) based on aluminium oxide/C8PA/pentacene and the kinetics of the transistor bias-induced degradation. Structural changes in the vapour-deposited C8PA monolayer, studied by Fourier Transform Infrared (FTIR) spectroscopy, are induced by annealing. Changes in the threshold voltage, subthreshold slope, field-effect mobility, and the transistor on-current are measured as functions of the bias stress time and fitted with stretched exponential functions. The presence of C8PA molecules physisorbed to the monolayer and/or the increased disorder between the aliphatic tails results in substantial degradation of the subthreshold slope and faster reduction in normalized mobility, while slowing the degradation of the threshold voltage. The removal of all physisorbed molecules and improved order between aliphatic tails achieved via optimized post-deposition annealing leads to an improved, microscopically-less-varied interface between C8PA and pentacene. Consequently, the degradation of the subthreshold slope becomes negligible, the reduction in normalized mobility becomes smaller and the degradation of the threshold voltage dominates. The equilibrium value of the normalized on-current after prolonged bias stress is ~ 0.16 regardless of the disorder in C8PA monolayer, indicating that even though the structure of the monolayer affects the kinetics of the transistor degradation process, the same bias stress condition ultimately leads to the same relative drop in the on-current

Insulator superconductor transition on solid inert gas substrates

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 $\epsilon_{r}$ 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 $h/4e^2$ and the crossover thickness close to 25 $\AA$ 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

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

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

Interfacial Layers of Small Molecule Organic Solar Cells

The influence of interfacial layers, introduced between electrodes and active layer, on organic solar cells was understood. Anode interfacial layer was made of vanadium oxide (V2O5) or 4,4′,4′′-Tris[phenyl(m-tolyl)amino]triphenylamine (m-MTDATA). V2O5 is an inorganic material and m-MTDATA is an organic material. Tris(8-hydroxyquinolinato)aluminium (Alq3) was chosen as cathode interfacial layer. Two thicknesses of 5 nm and 10 nm were considered for each of V2O5, m-MTDATA and Alq3. Modeling and simulation of devices was done using transfer matrix methodology for the measurement of optical electric field, device reflectance, power dissipation, absorptance and power re-distribution. Optical and electrical characterization of fabricated devices was done for the measurement of current density-voltage characteristics, device reflectance, thickness, refractive index and extinction coefficient. It was observed that device with m-MTDATA of 5 nm as anode interfacial layer and Alq3 of 5 nm as cathode interfacial layer resulted in better performance