Home  About us  Contact
 

Economic Application (economic + application)

Distribution by Scientific Domains
Engineering75%

Selected Abstracts

An economic application of the Dubovitskii,Milyutin version of the Maximum Principle

OPTIMAL CONTROL APPLICATIONS AND METHODS, Issue 6 2007
Siu Fai Leung
Abstract The Pontryagin Maximum Principle is well known in economics. There is a different and more general version of the Maximum Principle, first established by Dubovitskii and Milyutin (Dokl. Acad. Nauk SSSR 1963; 149:759,762; Zh. Vychisl. Mat. Mat. Fiz. 1965; 5:393,453), which is little known in economics and has never been applied to solve an economic optimal control problem. This paper introduces the Dubovitskii,Milyutin version of the Maximum Principle to economics and offers an economic application to illustrate the limitation of the conventional Maximum Principle and the usefulness of the Dubovitskii,Milyutin version. The Dubovitskii,Milyutin Maximum Principle should be an integral part of the economist's toolbox and be included in economics textbooks on dynamic optimization. Copyright © 2007 John Wiley & Sons, Ltd. [source]

Anwendung von Trapezblechstegen im Brückenbau

BETON- UND STAHLBETONBAU, Issue 9 2009
Längsschubtragverhalten von Betondübeln in Kombination mit Trapezblechstegen
Brückenbau; Entwurf und Konstruktion Abstract Trapezblechstege im Brückenbau kommen trotz der großen Vorteile, die diese Bauweise bietet, in Deutschland bisher nur an einem Pilotprojekt zur Anwendung. Durch die charakteristischen Eigenschaften des Trapezbleches entstehen konstruktive und wirtschaftliche Vorteile gegenüber herkömmlichen Brückenbauweisen. Allerdings lassen die aktuell gültigen Regelwerke aufgrund fehlender Kenntnis zum Tragverhalten und mangelnder Erfahrung keine wirtschaftliche Ausbildung zu. Dies zeigt sich am Beispiel des Pilotprojekts. Die Ausbildung der Verbundfuge wurde hier nur sehr unbefriedigend gelöst und verdeutlicht somit die Notwendigkeit einfacher und praktikabler Verbindungsmöglichkeiten. Am Institut für Leichtbau Entwerfen und Konstruieren der Universität Stuttgart wurde in Zusammenarbeit mit dem Institut für Konstruktion und Entwurf ein von der Forschungsvereinigung für Stahlanwendung e. V. (FOSTA) finanziertes Forschungsvorhaben bearbeitet, bei dem unterschiedliche Verbundfugenausbildungen numerisch und experimentell untersucht wurden. Der folgende Beitrag beschränkt sich auf die Verwendung von Betondübeln als Verbundmittel und stellt hierfür ein einfaches Bemessungskonzept für die Verbundsicherung unter Längsschubbeanspruchung im Grenzzustand der Tragfähigkeit vor. The use of corrugated steel webs in bridge constructions , Load bearing behaviour of concrete dowels in combination with corrugated steel webs under longitudinal shear Studies of the load bearing behaviour under shear force of integrated connections at composite bridge girders using corrugated steel webs. Up to now there is only one project in Germany, where the application of corrugated steel webs has been practiced in the field of composite bridges. Due to the characteristics of the corrugated steel web this construction method has constructive and economic advantages. However there is a lack of experiences and standards to fully utilize these advantages and to allow an economic application. Especially the first project in Germany expose some critical points. The design of the joint between the concrete slab and the corrugated steel web is actually not satisfactory and shows the need for simpler and more practicable connection methods. At the Institute for Lightweight Structures and Conceptual Design at Universität Stuttgart and together with the Institute of Structural Design, a research project, financed by Forschungsvereinigung für Stahlanwendung e. V. (FOSTA) was made. Within this project different types of composite joints were experimentally and numerically analysed. This paper deals only with the investigations of concrete dowels as connectors. On the basis of these studies simple design rules for shear connection in the ultimate limit state were developed. [source]

The Effect of the Estimation on Goodness-of-Fit Tests in Time Series Models

JOURNAL OF TIME SERIES ANALYSIS, Issue 4 2005
Yue Fang
Abstract., We analyze, by simulation, the finite-sample properties of goodness-of-fit tests based on residual autocorrelation coefficients (simple and partial) obtained using different estimators frequently used in the analysis of autoregressive moving-average time-series models. The estimators considered are unconditional least squares, maximum likelihood and conditional least squares. The results suggest that although the tests based on these estimators are asymptotically equivalent for particular models and parameter values, their sampling properties for samples of the size commonly found in economic applications can differ substantially, because of differences in both finite-sample estimation efficiencies and residual regeneration methods. [source]