An Algorithm for Clustered Data Generalized Additive Modelling with S-PLUS

We present a set of functions in S-PLUS to implement the clustered data generalized additive marginal modelling (CDGAM) strategy proposed by Berhane and Tibshirani (1998). A variety of working correlation structures are supported, and the regression basis may include components from the family of smoothing splines.

Asymptotic Dynamical Difference between the Nonlocal and Local Swift-Hohenberg Models

In this paper the difference in the asymptotic dynamics between the nonlocal and local two-dimensional Swift-Hohenberg models is investigated. It is shown that the bounds for the dimensions of the global attractors for the nonlocal and local Swift-Hohenberg models differ by an absolute constant, which depends only on the Rayleigh number, and upper and lower bounds of the kernel of the nonlocal nonlinearity. Even when this kernel of the nonlocal operator is a constant function, the dimension bounds of the global attractors still differ by an absolute constant depending on the Rayleigh number.Comment: 13 pages, LaTex fil

Ownership Restriction and Housing Value: Evidence from American Housing survey

Amendments to the Fair Lending Act have exempted an age restriction on ownership from fair housing prohibitions. This paper studies the economic impact of such ownership restriction on housing values. Using American Housing Survey data, we find that there is a significant premium attached to the restrictive covenant when other factors are controlled. In particular, we find that imposing age restriction on ownership increases the housing values by anywhere from 10.5% to 12.7%. At the average house value, this is equivalent to a dollar amount between $14,642 and$17,399. The estimates are robust to different specifications in hedonic equations.

Mosaic number and Tile number of Corner Connection Tiles

Lomonaco and Kauffman introduced knot mosaics in 2008 to model physical quantum states. These mosaics use a set of tiles to represent knots on $n x n$ grids. In 2023 Heap introduced a new set of tiles that can represent knots on a smaller board for small knots. Completing an exhaustive search of all knots or links, $K$, on different board sizes and types is the most common way to determine invariants for knots, such as the smallest board size needed to represent a knot, $m(K)$, and the least number of tiles needed to represent a knot, $t(K)$. In this paper, we propose a solution to an open question by providing a proof that all knots or links can be represented on corner connection mosaics using fewer tiles than traditional mosaics $t_c(K) < t(K)$, where $t_c(K)$ is the smallest number of corner connection tiles needed to represent knot \textit{K}. We also define bounds for corner connection mosaic size, $m_c(K)$, in terms of crossing number, $c(K)$, and simultaneously create a tool called the \textit{Corner Mosaic Complement} that we use to discover a relationship between traditional tiles and corner connection tiles. Finally, we construct an infinite family of links $L_n$ where the corner connection mosaic number $m_c(K)$ is known and provide a tool to analyze the efficiency of corner connection mosaic tiles.Comment: 24 pages, 14 figure

Multi-user lattice coding for the multiple-access relay channel

This paper considers the multi-antenna multiple access relay channel (MARC), in which multiple users transmit messages to a common destination with the assistance of a relay. In a variety of MARC settings, the dynamic decode and forward (DDF) protocol is very useful due to its outstanding rate performance. However, the lack of good structured codebooks so far hinders practical applications of DDF for MARC. In this work, two classes of structured MARC codes are proposed: 1) one-to-one relay-mapper aided multiuser lattice coding (O-MLC), and 2) modulo-sum relay-mapper aided multiuser lattice coding (MS-MLC). The former enjoys better rate performance, while the latter provides more flexibility to tradeoff between the complexity of the relay mapper and the rate performance. It is shown that, in order to approach the rate performance achievable by an unstructured codebook with maximum-likelihood decoding, it is crucial to use a new K-stage coset decoder for structured O-MLC, instead of the one-stage decoder proposed in previous works. However, if O-MLC is decoded with the one-stage decoder only, it can still achieve the optimal DDF diversity-multiplexing gain tradeoff in the high signal-to-noise ratio regime. As for MS-MLC, its rate performance can approach that of the O-MLC by increasing the complexity of the modulo-sum relay-mapper. Finally, for practical implementations of both O-MLC and MS-MLC, practical short length lattice codes with linear mappers are designed, which facilitate efficient lattice decoding. Simulation results show that the proposed coding schemes outperform existing schemes in terms of outage probabilities in a variety of channel settings.Comment: 32 pages, 5 figure