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Construction Procedure (construction + procedure)

Distribution by Scientific Domains
Business, Economics, Finance and Accounting60%

Selected Abstracts

Modelling of earth and water pressure development during diaphragm wall construction in soft clay

INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 13 2004
R. Schäfer
Abstract The influence of a diaphragm wall construction on the stress field in a soft clayey soil is investigated by the use of a three-dimensional FE-model of seven adjacent wall panels. The installation procedure comprises the excavation and the subsequent pouring of each panel taking into account the increasing stiffness of the placed fresh concrete. The soft clay deposit is described by a visco-hypoplastic constitutive model considering the rheological properties and the small-strain stiffness of the soil. The construction process considerably affects the effective earth and pore water pressures adjacent to the wall. Due to concreting, a high excess pore water pressure arises, which dissipates during the following construction steps. The earth pressure finally shows an oscillating, distinct three-dimensional distribution along the retaining wall which depends on the installation sequence of the panels and the difference between the fresh concrete pressure and the total horizontal earth pressure at rest. In comparison to FE-calculations adopting the earth pressure at rest as initial condition, greater wall deflections and surface ground settlements during the subsequent pit excavation can be expected, as the average stress level especially in the upper half of the wall is increased by the construction procedure of the retaining structure. Copyright © 2004 John Wiley & Sons, Ltd. [source]

Layout modeling and construction procedure for the arrangement of exhibition spaces in a fair

INTERNATIONAL TRANSACTIONS IN OPERATIONAL RESEARCH, Issue 4 2003
P. Schneuwly
Abstract This paper tackles a subset of layout problems that is not a subject of the scientific research to date: the arrangement of the exhibition spaces in a fair. A fair is a large-scale exhibition for goods and services; for example a trade fair or a regional fair. The layout problem of fairs consists in finding an acceptable layout for both the exhibitors, the visitors, and the organizer of the fair. A model for representing the layout of fairs is presented: the adjacency model. Based on the adjacency model, a construction procedure is developed that leads to the generation of alternative layout solutions. Numerical results for the layout of a real fair are reported. [source]

Some fundamental aspects of building protein structures from fragment libraries

PROTEIN SCIENCE, Issue 6 2004
J. Bradley Holmes
Abstract We have investigated some of the basic principles that influence generation of protein structures using a fragment-based, random insertion method. We tested buildup methods and fragment library quality for accuracy in constructing a set of known structures. The parameters most influential in the construction procedure are bond and torsion angles with minor inaccuracies in bond angles alone causing >6 Å C,RMSD for a 150-residue protein. Idealization to a standard set of values corrects this problem, but changes the torsion angles and does not work for every structure. Alternatively, we found using Cartesian coordinates instead of torsion angles did not reduce performance and can potentially increase speed and accuracy. Under conditions simulating ab initio structure prediction, fragment library quality can be suboptimal and still produce near-native structures. Using various clustering criteria, we created a number of libraries and used them to predict a set of native structures based on nonnative fragments. Local C,RMSD fit of fragments, library size, and takeoff/landing angle criteria weakly influence the accuracy of the models. Based on a fragment's minimal perturbation upon insertion into a known structure, a seminative fragment library was created that produced more accurate structures with fragments that were less similar to native fragments than the other sets. These results suggest that fragments need only contain native-like subsections, which when correctly overlapped, can recreate a native-like model. For fragment-based, random insertion methods used in protein structure prediction and design, our findings help to define the parameters this method needs to generate near-native structures. [source]

Formative Versus Reflective Indicators in Organizational Measure Development: A Comparison and Empirical Illustration

BRITISH JOURNAL OF MANAGEMENT, Issue 4 2006
Adamantios Diamantopoulos
A comparison is undertaken between scale development and index construction procedures to trace the implications of adopting a reflective versus formative perspective when creating multi-item measures for organizational research. Focusing on export coordination as an illustrative construct of interest, the results show that the choice of measurement perspective impacts on the content, parsimony and criterion validity of the derived coordination measures. Implications for practising researchers seeking to develop multi-item measures of organizational constructs are considered. [source]