Simple perfect squared squares and 2 * 1 squared rectangles of order 26

Simple Perfect Squared Squares and 2 × 1 Squared Rectangles of Orders 21 to 24

Simple perfect squared square of lowest order

This note is to report the existence of a simple perfect dissection of a square into 21 unequal squares.

Squarability of rectangle arrangements

We study when an arrangement of axis-aligned rectangles can be transformed into an arrangement of axisaligned squares in R while preserving its structure. We found a counterexample to the conjecture of J. Klawitter, M. Nöllenburg and T. Ueckerdt whether all arrangements without crossing and side-piercing can be squared. Our counterexample also works in a more general case when we only need to p...

Optimal variance estimation without estimating the mean function

We study the least squares estimator in the residual variance estimation context. We show that the mean squared differences of paired observations are asymptotically normally distributed. We further establish that, by regressing the mean squared differences of these paired observations on the squared distances between paired covariates via a simple least squares procedure, the resulting varianc...

A Channel Estimation Method for MIMO-OFDM Systems

This paper proposes a simple and efficient method for MIMO-OFDM channel estimation using parameters similar to HIPERLAN/2. Both preamble and pilot structures are compared in a 2 transmit-2 receive Space Frequency Trellis Coded system and the Mean Squared Error is used as a metric for comparing the results. It is shown, via simulation, that the proposed methods incur a maximum loss of approximat...