This paper investigates the fundamental limits for detecting a high-dimensional sparse matrix contaminated by white Gaussian noise from both the statistical and computational perspectives. We consider p×pmatrices whose rows and columns are individually k-sparse. We provide a tight characterization of the statistical and computational limits for sparse matrix detection, which precisely describe ...

Since the mid-1970s, rice consumption in Nigeria has risen tremendously at about 10% per annum due to changes in consumer preference. Most public and private sector interventions programmes at increasing the productive capacities of various factors within the system notwithstanding, domestic production has not been able to meet the local demand leading to considerable import, which today stood ...

The purpose of this paper is to construct a weak hyper semi-quantale as a generalization of the concept of semi-quantale and used it as an appropriate hyperlattice-theoretic basis to formulate new lattice-valued topological theories. Based on such weak hyper semi-quantale, we aim to construct the notion of a weak hypervalued-topology as a generalized form of the so-called lattice-valued t...

We consider two closely related problems: planted clustering and submatrix localization. In the planted clustering problem, a random graph is generated based on an underlying cluster structure of the nodes; the task is to recover these clusters given the graph. The submatrix localization problem concerns locating hidden submatrices with elevated means inside a large real-valued random matrix. O...

Quality of seeds of three cultivars (IPSA Seem-2, BU Seem-3 and IPSA Seem5) of lablab bean (Lablab purpureus L. Sweet) collected from crops planted in three different dates (15 May, 15 July, and 15 September 2003) was assessed in respect of different parameters. The maximum percentage of seeds of cv. IPSA Seem-2 was germinated (95.67) whereas, BU Seem-3 had the maximum electrical conductivity (...

Biodiversity experiments show that increases in plant diversity can lead to greater biomass production, and some researchers suggest that high diversity plantings should be used for bioenergy production. However, many methods used in past biodiversity experiments are impractical for bioenergy plantings. For example, biodiversity experiments often use intensive management such as hand weeding to...

This my final project paper for the class 18.S996: Algorithmic Aspects of Machine Learning, taught in Fall 2013 by Prof. Ankur Moitra. In this note, I will explain the spectral method for partitioning a graph as used in the following two papers: [1] N. Alon, M. Krivelevich, and B. Sudakov, Finding a large hidden clique in a random graph. [4] F. McSherry, Spectral partitioning of random graphs. ...

Selected PCB congeners (PCB 52, 77, and 153) singly and in mixtures were spiked and aged in soil microcosms and subsequently planted with switchgrass (Panicum virgatum) or poplar (Populus deltoids x nigra DN34). The planted reactors showed significantly greater reductions in PCB parent compounds when compared to unplanted systems after 32 weeks, both in single congener exposures and when all th...

In this article we will present some problems that have weak symmetries. In contrast to a proper symmetry, a weak symmetry acts only on a subset of the variables and preserves the feasibility state only with respect to a subset of the constraints. Therefore, breaking weak symmetries with standard techniques would lead to a loss of solutions. This article presents also a modelling technique whic...

In this paper, we classify all generalized quadrangles weakly embedded of degree 2 in projective space. More exactly, given a (possibly infinite) generalized quadrangle Γ = (P,L, I ) and a map π from P (respectively L) to the set of points (respectively lines) of a projective space PG(V ), V a vector space over some skew field (not necessarily finite-dimensional), such that: (i) π is injective ...