Differentially Private Regression for Discrete-Time Survival Analysis

In survival analysis, regression models are used to understand the effects of explanatory variables (e.g., age, sex, weight, etc.) to the survival probability. However, for sensitive survival data such as medical data, there are serious concerns about the privacy of individuals in the data set when medical data is used to fit the regression models. The closest work addressing such privacy concerns is the work on Cox regression which linearly projects the original data to a lower dimensional space. However, the weakness of this approach is that there is no formal privacy guarantee for such projection. In this work, we aim to propose solutions for the regression problem in survival analysis with the protection of differential privacy which is a golden standard of privacy protection in data privacy research. To this end, we extend the Output Perturbation and Objective Perturbation approaches which are originally proposed to protect differential privacy for the Empirical Risk Minimization (ERM) problems. In addition, we also propose a novel sampling approach based on the Markov Chain Monte Carlo (MCMC) method to practically guarantee differential privacy with better accuracy. We show that our proposed approaches achieve good accuracy as compared to the non-private results while guaranteeing differential privacy for individuals in the private data set.Comment: 19 pages, CIKM1

Electron and muon parameters of EAS and the composition of primary cosmic rays in 10(15) to approximately 10(16) eV

Estimation of the relative intensities of protons and heavy nuclei in primary cosmic rays in the energy region 10 to the 15th power approx. 10 to the 17th power eV, was done by a systematic comparison between all available observed data on various parameters of extensive air showers (EAS) and the results of simulation. The interaction model used is an extrapolation of scaling violation indicated by recent pp collider results. A composition consisting of various percentages of Fe in an otherwise pure proton beam was assumed. Greatest overall consistency between the data and the simulation is found when the Fe fraction is in the region of 25%

The effect of the ground plane size and the height on small PIFA

This is the post-print version of the article - Copyright @ ISAP 201

A novel technique to improve gain in transparent UWB antennas

A novel technique to improve the performance of AgHT-8 transparent polymer antennas is proposed in this paper. A spit-ring resonator is introduced on the radiating patch to enhance gain. The resonator basically concentrates the radiating energy to the central area of the patch thus improving gain. The designed antenna demonstrates good gain while maintaining the original transparency of the material. Such an antenna inscribed on the commercially available AgHT-8 sun shielding film material makes it a viable option for wireless applications like in-house base stations and applications requiring fast data rate transfers which can be mounted on windows and glass panels. © 2011 IEEE.Solutia Inc., St. Louis, Missouri, US

Origins of Hidden Sector Dark Matter I: Cosmology

We present a systematic cosmological study of a universe in which the visible sector is coupled, albeit very weakly, to a hidden sector comprised of its own set of particles and interactions. Assuming that dark matter (DM) resides in the hidden sector and is charged under a stabilizing symmetry shared by both sectors, we determine all possible origins of weak-scale DM allowed within this broad framework. We show that DM can arise only through a handful of mechanisms, lending particular focus to Freeze-Out and Decay and Freeze-In, as well as their variations involving late time re-annihilations of DM and DM particle anti-particle asymmetries. Much like standard Freeze-Out, where the abundance of DM depends only on the annihilation cross-section of the DM particle, these mechanisms depend only on a very small subset of physical parameters, many of which may be measured directly at the LHC. In particular, we show that each DM production mechanism is associated with a distinctive window in lifetimes and cross-sections for particles which may be produced in the near future. We evaluate prospects for employing the LHC to definitively reconstruct the origin of DM in a companion paper.Comment: 32 pages, 19 figures; v2: references added, published versio

A novel technique and soldering method to improve performance of transparent polymer antennas

This article is archived here with permission from IEEE - Copyright @ 2010 IEEEA novel technique and a non-thermal soldering method to improve the performance of AgHT-8 transparent polymer antennas are proposed in this paper. The proposed technique involves the removal of the coating layer at areas on the CPW ground and feed line where the connectors of the coaxial feed or legs of the SMA connectors will be attached, and applying a coat of silver paint on the exposed areas before cold soldering the coaxial connections or SMA connector legs. The non-thermal or cold soldering using electrically conductive paste enables direct soldering of the co-axial feed points or connector legs which cannot otherwise be done with hot or thermal soldering. This type of connection greatly enhances the performance of the AgHT-8 polymer antennas compared to coaxial feed point connections through hot soldered copper pads glued to the surface of the polymer coating. The proposed technique also gives a stronger connection bond than directly cold soldering the feed points or connectors to the smooth surface of the AgHT-8 material. Furthermore, the copper pad connection technique also introduces additional losses contributed by the adhesive properties of the glue used. This proposed novel technique and soldering method may be extended to enhance antenna performance made from other similar transparent conductive polymers like IT

A non-thermal soldering technique to improve polymer based antenna performance

Copyright @ 2010 EuMCA non-thermal soldering technique using cold solder or electrically conductive epoxy for connecting SMA connectors to polymer based antennas is proposed in this paper. The proposed technique prevents damage to the polymer due to the solder iron heat and also the loss of efficiency through the use of indirect connections of the coaxial feed via copper pads glued to the antenna. The direct connection of the feed points via SMA connectors on to a transparent antenna designed on AgHT-8 material has been demonstrated. The method can also be applied to solder the coaxial feed points directly to the antenna instead of using copper pads which will introduce additional reflection losses. The technique involves the use of colder soldering instead of hot soldering so as to not damage the polymer based antenna as well as improve the efficiency of the antenna

The effect of the mutual coupling on small reconfigurable antennas

Copyright @ ISAP 201