Friedel Peldschus

Multi-Objective Decision-Making for Road Design

Abstract Multi‐objective analysis is a popular tool to solve many economic, managerial and construction problems. The objective of this research is to develop and implement a methodology for multi‐objective optimization of multi‐alternative decisions in road construction. After a rough overview of the articles dealing with the multi‐objective decision and assessment of road design alternatives described by discrete values, Multi‐Objective Optimization on the basis of the Ratio Analysis (MOORA) method was selected. This method focuses on a matrix of alternative responses on the objectives. A case study demonstrates the concept of multi‐objective optimization of road design alternatives and the best road design alternative is determined.

Experience of the game theory application in construction management

Abstract The game theory allows mathematical solutions of conflict situations. Besides the fairly established application to economical problems, approaches to problems in construction operation have been worked out. An overview of applications is given. Solution strategies for such engineering problems are collected. Furthermore, concrete application examples are presented and an overview of further potential applications is given. Solutions of two‐person zero‐sum games are discussed as well as approaches to fuzzy games.

LEVI 3.0—MULTIPLE CRITERIA EVALUATION PROGRAM FOR CONSTRUCTION SOLUTIONS

Abstract The paper considers the main methods employed to solve one-sided and two-sided problems of the game theory. For the one-sided problems only the method of solution “distance to the ideal point” is discussed. For the two-sided problems a distinction is made between games with rational behaviour and games against nature. The main principles of the strategies are as follows: simple min-max principle, extended min-max principle, Walds rule, Savage criterion, Hurwiczs rule, Laplaces rule, Bayess rule, Hodges-Lehmann rule. The questions transforming the decisionmaking matrix are considered: vectorial transformation, linear transformation, linear transformation according to Juttlers or Stopps method, non-linear transformation according to Peldschus. The article gives the description of a program package as well as an example of an investment variant estimation. The program LEVI 3.0 is a result of the cooperation between the VGTU and HTWK. This article provides description of a program package as we...

The analysis of the quality of the results obtained with the methods of multi‐criteria decisions

Abstract For many decades we have been dealing with problems of multi‐criteria decisions. Numerous methods have been developed in this field and new methods are continuously being created. In the light of a great number of methods currently proposed, it is difficult to gain a profound overview. Comparisons on the performance of various methods are done to a small extent only. When applying the methods, in some cases many mathematical operations are performed, which renders it impossible to sufficiently assess their effect with such a complexity. It is therefore aimed at analysing the peculiarities of several methods in a critical review and to give hints for possible consequences. The analysis is primarily concentrated on the normalisation of indices in the mapping to the interval [1; 0] or [1; ∼ 0]. This includes linear functions (the relative difference and the calculation with interval boundaries) and non‐linear functions (the hyperbolic function, the quadratic and cubic function, the square root and t...

The effectiveness of assessments in multiple criteria decisions

For the solution of multiple criteria decisions, the comparative effectiveness of different alternatives is expressed by non-dimensional values. When repeating calculations with a modified set of alternatives, the solution may vary depending on the used transformation method. Also the possibility of an unintentional weighing between maximisation and minimisation cannot be excluded. Several normalisation formulae are investigated and a suggestion for a stable solution is discussed, giving the decision maker the possibility to better evaluate the quality of his solution.

Multiple‐criteria analysis in the construction of motorways

Abstract Several construction variants are discussed for the extension of the motorway network in Thuringia (Germany). The best variant is determined according to several criteria: construction period, costs, durability, environmental protection and economic viability. After the characterisation of the considered construction solutions a numerical comparison is made using the software LEVI 3.0. Thereby the optimal variant is chosen taking into account the mentionned criteria and the solution is explained.

Professor Edmundas Kazimieras Zavadskas: His Academic Research, School Of Thought, And Most Eminent Results Of His Work

Multiple Criteria Decision Making (MCDM) substantially evolved during the past decades and became one of the most important areas in Operational Research in Civil Engineering and Management Science. In Europe, this area is closely related to research performed by Professor Edmundas Kazimieras Zavadskas. The paper presents a review of extensive scientifi c work of Professor E.K. Zavadskas on the occasion of his 70th birthday. The paper also highlights his research carrier, and lists some of his fi elds of activity and research results including monographs, books, prized publications, memberships in various associations and other areas.

Recent findings from numerical analysis in multi-criteria decision making

Numerical investigations have shown, that different function profiles for the description of variants are possible. This should be taken into account for mapping of characteristic values on a dimensionless interval [1; 0] or [1; ~ 0]. The purpose of the study was to investigate the impact of linear, concave and convex function profiles for mapping on a dimensionless interval (normalisation). Ten different formulas were examined. The analysis of calculation approaches in the past revealed that only a single transformation formula was used for all criteria. A specific investigation into a functional character of the different initial values has not been done. Hence, the question whether this being a real or fictitious calculation was not answered. The performed analyses are supposed to contribute to the prevention of erroneous decisions.

INFLUENCE OF CHISEL SHARE FOR THE DESTRUCTION OF CONCRETE

Abstract The energy shares occurring in the chiselling process were investigated in order to increase the productivity of the manual destruction of concrete. Apart from the influences of notch energy and cleaving energy, the energy loss due to friction forces was considered. As a result two new chisel forms were developed as a combination of sharp cutting edge and steep wedge. The effectiveness of these chisels was tested under experimental conditions as well as under reality conditions. It was found that the application of lateral tips at the chisel leads to an improved processing performance.

EXPERIMENTAL INVESTIGATIONS IN CHISELLING SOLID CONCRETE

Abstract Experimental research was performed for analysing the chiselling process. The conditions of crack formation and crack propagation have been analysed. In the first step impact tests with a standard chisel shapes and with a pointed chisel were performed. These tests represented the basic investigations into the chisel load effects on mechanical processing of concrete. In the next step precise modifications were applied to the flat-chisel cutting edge with the aim of improving the cutting-edge geometry.