In this paper, we study the problem of answering queries about private data that is spread across multiple different databases. For instance, a medical researcher may want to study a possible correlation between travel patterns and certain types of illnesses. The necessary information exists today – e.g., in airline reservation systems and hospital records – but it is maintained by two separate...

Measuring the topological overlap of two graphs becomes important when assessing the changes between temporally adjacent graphs in a time-evolving network. Current methods depend on the fraction of nodes that have persisting edges. This breaks down when there are nodes with no edges, persisting or otherwise. The following outlines a proposed correction to ensure that correlation metrics have th...

Let X = (Xij ) be a p × n data matrix, where the n columns form a random sample of size n from a certain p-dimensional distribution. Let R = (ρij ) be the p × p sample correlation coefficient matrix of X, and S = (1/n)X(n)(X(n))∗ − X̄X̄∗ be the sample covariance matrix of X, where X̄ is the mean vector of the n observations. Assuming that Xij are independent and identically distributed with finite...

В работе излагаются особенности влияния длины инвестиционного горизонта на выбор инвестором оптимального для себя портфеля. Приводятся условия, при которых неэффективные портфели для однопериодного случая становятся эффективными с увеличением инвестиционного горизонта. Сравниваются два различных подхода к описанию предпочтений инвестора при выборе портфеля. Один из подходов основывается на крив...

Understanding and quantifying dependence is at the core of all modelling efforts in financial econometrics. The linear correlation coefficient, which is the far most used measure to test dependence in the financial community and also elsewhere, is only a measure of linear dependence. This means that it is a meaningful measure of dependence if asset returns are well represented by an elliptical ...

Let {Xk,i; i≥ 1, k ≥ 1} be an array of i.i.d. random variables and let {pn;n ≥ 1} be a sequence of positive integers such that n/pn is bounded away from 0 and∞. ForWn =max1≤i 1/2), (...

A destoner fractionation process was used to separate distillers dried grains with solubles (DDGS) into streams with various compositions. Results showed that destoner fractionation was somewhat efficient and effective. Runs with 8° angle and 27.5 percent air flow resulted in the highest value of protein and oil, which the light fraction had 28.15% protein, 10.50% oil, while the heavy fraction...

The product-moment correlation coefficient is often viewed as a natural measure of dependence. However, this equivalence applies only in the context of elliptical distributions, most commonly the multivariate gaussian, where linear correlation indeed sufficiently describes the underlying dependence structure. Should the true probability distributions deviate from those with elliptical contours,...

Let X = (Xij) be a p × n data matrix, where the n columns form a random sample of size n from a certain p-dimensional distribution. Let R = (ρij) be the p × p sample correlation coefficient matrix of X; and S = (1/n)X ( X )∗ − X̄X̄∗ be the sample covariance matrix of X, where X̄ is the mean vector of the n observations. Assuming that Xij ’s are independent and identically distributed with finite f...

In this paper, we investigate whether text from a Community Question Answering (QA) platform can be used to predict and describe real-world attributes. We experiment with predicting a wide range of 62 demographic attributes for neighbourhoods of London. We use the text from QA platform of Yahoo! Answers and compare our results to the ones obtained from Twitter microblogs. Outcomes show that the...