Combinatorial Designs with Two Singular Values I. Uniform Multiplicative Designs

In this and a sequel paper [10] we study combinatorial designs whose incidence matrix has two distinct singular values.These generalize 2-(v, k, É) designs, and include partial geometric designs and uniform multiplicative designs.Here we study the latter, which are precisely the nonsingular designs.We classify all such designs with smallest singular value at most, generalize the Bruck-Ryser-Chowla conditions, and enumerate, partly by computer, all uniform multiplicative designs on at most 30 points.combinatorics;matrices;singularities

Combinatorial Designs with Two Singular Values II. Partial Geometric Designs

In this and an earlier paper [17] we study combinatorial designs whose incidence matrix has two distinct singular values.These generalize (v, k, ë) designs, and include uniform multiplicative designs and partial geometric designs.Here we study the latter, which are precisely the designs with constant replication and block size.We collect most known results, give new characterization results, and we enumerate, partly by computer, all small ones.matrices;singularities;geometry;combinatorics

Some Spectral and Quasi-Spectral Characterizations of Distance-Regular Graphs

In this paper we consider the concept of preintersection numbers of a graph. These numbers are determined by the spectrum of the adjacency matrix of the graph, and generalize the intersection numbers of a distance-regular graph. By using the preintersection numbers we give some new spectral and quasi-spectral characterizations of distance-regularity, in particular for graphs with large girth or large odd-girth

ArcMap Hydrology Toolset: WPES, How Do I...? Quick Guide

This document provides guidance for performing hydrologic tasks using the Hydrology Toolset in ArcMap 10.x (ArcGIS Desktop). Covered here are an overview of the uses and limitations of the tools within the Hydrology Toolset, related tools from from additional ArcGIS toolsets, and step-by-step instructions for hydrologic workflows including digital elevation model (DEM) preparation, pit fill detection, burning in culverts for proper flow path routing, watershed and stream network delineation, and flow network statistics

Survey Control with GNSS Receiver: WPES, How Do I...? Quick Guide

This document is a quick guide to establishing survey control points using a Global Navigation Satellite Systems (GNSS) receiver and processing collected point coordinate data. The WPES Research Group uses a Trimble NetR9 GNSS reference receiver, which is reflected in the specific sequences of button presses outlined in the data profile setup, field operation, and data download sections. Readers using a different receiver may still find the general workflow overview useful and should be able to use the data post-processing section directly

ArcMap Basics: WPES, How Do I...? Quick Guide

This document is a quick guide to performing common geospatial tasks in ArcMap 10.x (ArcGIS Desktop) for new users. Covered are basic navigation of the ArcMap window; importing, opening, querying, editing, and exporting data; and map preparation. In many cases, there are multiple ways to accomplish different tasks; presented here are the methods the author finds easiest or most straightforward. Mouse click sequences and menu/tool layout may differ if using previous versions of ArcMap