45 research outputs found

    Road Scholar Core Course #1 - Asset Management

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    This course provides a detailed overview of the concepts of asset management and how to apply these concepts to the planning and operations of a local public agency. This course will also provide detailed information on the LTAP Data Management System (DMS) and the tools and resources available to assist in your Pavement Asset Management Plan (PAMP) preparation. While several components can make up a transportation asset management plan, this course will focus on pavement management and how to identify the condition of existing road networks. Attendees will also be presented effective methods for establishing priorities and developing policies and communication techniques that inform stakeholders and the public of the current condition of the road network. Key Concepts in this course: LTAP Data Management System and PAMP Resources available GIS tools and resources for PAMP Network Level Analysis – Funding Gap Identification Asset Management Principals Performance Measure

    Roundabout Maintenance Manual

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    In recent years, roundabouts have been rapidly growing in popularity. As a result, many communities are installing them in their roadways; however, they are encountering difficulties in maintaining them. Uneducated workers can cause damage to roundabouts and to themselves, costing cities time and money. This project aims to create a guide for communities new to roundabouts in order to reduce damages and unnecessary maintenance costs. Data was gathered by determining the most common maintenance questions and problems along with what information was already available on roundabout maintenance. Next, agencies most experienced with roundabouts were surveyed on the best maintenance practices. The responses from interview subjects gave detailed information on winter maintenance, summer maintenance, pavement maintenance, and vehicle and pedestrian access during maintenance activities. The data was compiled to create the roundabout maintenance manual. The guide created from the data collection will be helpful for communities new to roundabouts and serve as a reference for agencies in Indiana and surrounding states. In future years, the methods established in this guide should be re-evaluated and updated

    On the relation of Voevodsky's algebraic cobordism to Quillen's K-theory

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    Quillen's algebraic K-theory is reconstructed via Voevodsky's algebraic cobordism. More precisely, for a ground field k the algebraic cobordism P^1-spectrum MGL of Voevodsky is considered as a commutative P^1-ring spectrum. There is a unique ring morphism MGL^{2*,*}(k)--> Z which sends the class [X]_{MGL} of a smooth projective k-variety X to the Euler characteristic of the structure sheaf of X. Our main result states that there is a canonical grade preserving isomorphism of ring cohomology theories MGL^{*,*}(X,U) \tensor_{MGL^{2*,*}(k)} Z --> K^{TT}_{- *}(X,U) = K'_{- *}(X-U)} on the category of smooth k-varieties, where K^{TT}_* is Thomason-Trobaugh K-theory and K'_* is Quillen's K'-theory. In particular, the left hand side is a ring cohomology theory. Moreover both theories are oriented and the isomorphism above respects the orientations. The result is an algebraic version of a theorem due to Conner and Floyd. That theorem reconstructs complex K-theory via complex cobordism.Comment: LaTeX, 18 pages, uses XY-pi

    Equivariant cohomology and analytic descriptions of ring isomorphisms

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    In this paper we consider a class of connected closed GG-manifolds with a non-empty finite fixed point set, each MM of which is totally non-homologous to zero in MGM_G (or GG-equivariantly formal), where G=Z2G={\Bbb Z}_2. With the help of the equivariant index, we give an explicit description of the equivariant cohomology of such a GG-manifold in terms of algebra, so that we can obtain analytic descriptions of ring isomorphisms among equivariant cohomology rings of such GG-manifolds, and a necessary and sufficient condition that the equivariant cohomology rings of such two GG-manifolds are isomorphic. This also leads us to analyze how many there are equivariant cohomology rings up to isomorphism for such GG-manifolds in 2- and 3-dimensional cases.Comment: 20 pages, updated version with two references adde

    Orbit spaces of free involutions on the product of two projective spaces

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    Let XX be a finitistic space having the mod 2 cohomology algebra of the product of two projective spaces. We study free involutions on XX and determine the possible mod 2 cohomology algebra of orbit space of any free involution, using the Leray spectral sequence associated to the Borel fibration XXZ2BZ2X \hookrightarrow X_{\mathbb{Z}_2} \longrightarrow B_{\mathbb{Z}_2}. We also give an application of our result to show that if XX has the mod 2 cohomology algebra of the product of two real projective spaces (respectively complex projective spaces), then there does not exist any Z2\mathbb{Z}_2-equivariant map from SkX\mathbb{S}^k \to X for k2k \geq 2 (respectively k3k \geq 3), where Sk\mathbb{S}^k is equipped with the antipodal involution.Comment: 14 pages, to appear in Results in Mathematic

    Geometric K-Homology of Flat D-Branes

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    We use the Baum-Douglas construction of K-homology to explicitly describe various aspects of D-branes in Type II superstring theory in the absence of background supergravity form fields. We rigorously derive various stability criteria for states of D-branes and show how standard bound state constructions are naturally realized directly in terms of topological K-cycles. We formulate the mechanism of flux stabilization in terms of the K-homology of non-trivial fibre bundles. Along the way we derive a number of new mathematical results in topological K-homology of independent interest.Comment: 45 pages; v2: References added; v3: Some substantial revision and corrections, main results unchanged but presentation improved, references added; to be published in Communications in Mathematical Physic

    Primordial Nucleosynthesis for the New Cosmology: Determining Uncertainties and Examining Concordance

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    Big bang nucleosynthesis (BBN) and the cosmic microwave background (CMB) have a long history together in the standard cosmology. The general concordance between the predicted and observed light element abundances provides a direct probe of the universal baryon density. Recent CMB anisotropy measurements, particularly the observations performed by the WMAP satellite, examine this concordance by independently measuring the cosmic baryon density. Key to this test of concordance is a quantitative understanding of the uncertainties in the BBN light element abundance predictions. These uncertainties are dominated by systematic errors in nuclear cross sections. We critically analyze the cross section data, producing representations that describe this data and its uncertainties, taking into account the correlations among data, and explicitly treating the systematic errors between data sets. Using these updated nuclear inputs, we compute the new BBN abundance predictions, and quantitatively examine their concordance with observations. Depending on what deuterium observations are adopted, one gets the following constraints on the baryon density: OmegaBh^2=0.0229\pm0.0013 or OmegaBh^2 = 0.0216^{+0.0020}_{-0.0021} at 68% confidence, fixing N_{\nu,eff}=3.0. Concerns over systematics in helium and lithium observations limit the confidence constraints based on this data provide. With new nuclear cross section data, light element abundance observations and the ever increasing resolution of the CMB anisotropy, tighter constraints can be placed on nuclear and particle astrophysics. ABRIDGEDComment: 54 pages, 20 figures, 5 tables v2: reflects PRD version minor changes to text and reference
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