ADVANCES IN DECISION ANALYSIS. EFFICIENT METHODS IN FINANCE

Decision analysis offer workable solutions in domain such as the environment, health and medicine, engineering and operations research and finance. In finance area we can observe a big variety of method and techniques for research fluctuates from economy and financial date. Most economic decisions are related to monetary variables. Since money has a capacity to connect the present and the future, conflicts among long�run and short�run economic goals and uncertainties of the future make economic decisions very complicated. In this paper we will introduce some models to show how monetary variables can be investigated real aspects of economic development. We discusses problems encountered in financial models, describes efficient method and show how to apply them to practical problems in financedecision analysis, mathematical modeling, dynamic models, money

REENGINEERING AS AN EFFICIENT SOLUTION TO REDESIGN ACTIVITIES AND PROCESSES OF AN ENTERPRISE

The paper shows a series of opportunities linked to the technological, human and economical reengineering of activities and technological processes developed in a modern enterprise, adding new dimensions in the efficient development, on the market principles, in argument with the desiderate of the durable development of the society. Starting with these considerations we designed aspects linked to: business reengineering implementation, stages of this process, accentuating the management methods, delimitation on areas of activity of the effects on reengineering action.business reengineering process, reengineering enterprise, models and methods for reengineering project

Elastic-plastic Interactive Buckling of Thin-walled Steel Compression Members

In the actual design codes the interaction formula for local and overall buckling modes of thin-walled steel compression (TWSC) members, the effect of local buckling. is introduced by means of effective strength of short members. This paper proposes to replace, into the Ayrton-Perry interaction formula, the short member effective strength, which is based on the effective width approach by the plastic strength evaluated by means of local plastic mechanism analysis. There are some papers by Murray et al. [1,2,3], in which the plastic mechanisms corresponding to the local buckling of plates and TWSC members in compression are analysed. On this basis, the local·overall interactive buckling modes can be regarded as interaction between local rigid-plastic mode and overall-elastic one, but until now it was difficult to couple these two modes into an adequate interactive equation. The paper shows the use of proposed plastic-elastic approach for the analysis of some series of plain and lipped channel specimens in compression. Comparisons with test and EUROCODE 3 results are presented

Plastic Strength of Thin-walled Members

Failure of thin-walled cold-formed members in compression is always characterized by a local plastic mechanisms, either a stub or slender column is referred. Starting from this observation, the authors suggest for the interactive local-overall buckling analysis to use instead of traditional effective section , the sectional plastic mechanism strength. This is a new approach and for this reason it is compared with another one, namely the Direct Strength Method. Experimental results and advanced FEM simulations are used to evaluate the two methods. Comparisons with European and American relevant design codes are also presented in the paper

Reengineering as an Efficient Solution to Redesign Activities and Processes of an Enterprise

The paper shows a series of opportunities linked to the technological, human and economical reengineering of activities and technological processes developed in a modern enterprise, adding new dimensions in the efficient development, on the market principles, in argument with the desiderate of the durable development of the society. Starting with these considerations we designed aspects linked to: business reengineering implementation, stages of this process, accentuating the management methods, delimitation on areas of activity of the effects on reengineering action.business reengineering process, reengineering enterprise, models and methods for reengineering project

ROMANIA’S ECONOMIC GROWTH IN THE CURRENT INTERNATIONAL CONTEXT

Present and future economic growth is increasingly dependent on trends in the global economy. They lead to an intertwining of the economic progress at a national-regional-global level. In particular to bearing economic integration, globalization, globalization of economic, political multipolarity, expanding economy on a continental and global level, etc. The effects of these changes can be both beneficial and negative, so we proposed a study on the evolution of parameters characterizing both economic growth and the evolution of this growth in Romania in the current international context

Buckling Mode Interaction in Cold-formed Steel Columns and Beams

The buckling behaviour of cold-formed steel columns and beams is far from simple. The three generic forms of buckling, namely local buckling, distortional buckling and overall buckling, generally have different wavelengths and are usually restricted to different span ranges. However, there is also the possibility of interaction among these buckling modes at a certain span length. Thus, local plate buckling and distortional buckling may occur together with lateral-torsional buckling in such a way that they all have an influence on the ultimate load carrying capacity of a member. The influence of local buckling is taken into consideration in design codes by using either an effective width or an effective thickness for the plate element under consideration. However, the consideration of distortional buckling is less-well developed in the codes and the effect of its interaction with other buckling modes is far from clear. Another factor which influences the ultimate load carrying capacity of a thin-walled section is the interaction of compression force and bending moment. In current design codes, this is usually limited by a certain allowable stress in the extreme fibres of the cross-section. For a stocky member which is not subject to buckling, this is a reasonable assumption. However, for potentially unstable members, the behaviour is complicated and, in most cases, the test results are scattered high above the predictions given by the design codes. Generalised Beam Theory (GBT) [1-3] can provide explicit analytical expressions for the problems associated with the various interactions of the alternative buckling modes and also the interactions associated with combinations of axial load and bending. This paper, therefore, makes particular use of GBT in assessing the influence of local buckling and distortional buckling on lateral-torsional buckling and the interaction of compression force and bending moment. Based on analyses using GBT together with comparisons with available test results, conclusions are presented which the authors hope will be of benefit for future design codes

Numerical parametric study on corrugated web built-up beams with pinned end supports

Cold-formed steel elements are commonly used in construction due to their advantages, such as material savings and reduced self-weight. Such advantages can be significantly enlarged by using built-up solutions. Such solutions have been presented in the literature over the past few decades. The most common way to assemble such elements are using screws or bolts. However, the developments in the welding processes also lead to other solutions, such as continuous (laser or MIG brazing) or discrete (spot welding). Corrugated web beams are one of these built-up solutions. On the basis of previous experimental and numerical studies on such built-up beams, it was concluded that the capacity of the cold-formed steel built-up steel beams with the corrugated web with fixed end supports is highly affected by the type of connections and the geometry of the system and components, especially its corrugated web and shear panels near supports. To find the optimal geometry of such beams with nominally pinned end supports, the paper starts by summarising the previous experimental investigations on cold-formed steel built-up corrugated web beams and, based on a calibrated numerical model, presents the parametric numerical investigation of such beams with different configurations. The influence of several parameters has been investigated, i.e. the influence of different end supports conditions for beams with single and double web, the influence of the number of spot welds on flanges, the influence of changing from discrete to continuous connections between beam components, the influence of the distance between spot welds on flanges, influence of the flange's thickness, the influence of corrugated web thickness and the influence of the shear panel thickness. The parametric study shows that changing end support conditions can significantly reduce the complexity of the analysed beam support and its cost without a significant decrease in beam performances related to its rigidity and bending capacity. The new solution presented of corrugated web beams with double corrugated web shows a significant contribution in flexural rigidity and bending capacity. Changing the type of connection between beam elements from discrete spot welding to continuous connection results in a higher capacity and rigidity of these beams. On the other hand, increasing the number of spot welds from 2 to 3 per corrugation between the web and the flanges can have a certain influence on the increase of the ultimate bending capacity while initial flexural stiffness remains almost the same. The distance between the spot welds on the flanges shows a very small influence on the behavior of the beam. Increasing the thicknesses of the beam elements can significantly increase the flexural stiffness and bending capacity of the beam, and the optimal beam configuration will be investigated in future studies.This work has been supported in part by Croatian Science Foundation under the project UIP-2020-02-2964 and by a grant of the Ministry of Research, Innovation and Digitization, CCCDI - UEFISCDI, Romania, project number PN-III-P2-2.1-PTE-2021-0237, within PNCDI III

Positive evolution in economic forecasting. Case study: the evolution of a company’s capital

For the economic sciences, mainly for the planning and organization disciplines, the models display a range of varieties.  For the last decades, though, the mathematics-based models seem to be the trend, partly because of their ability to rigorously concentrate the essentials and also to be programmed via the computer-based techniques, thus creating together an unheard of instrument of scientific investigation, a resourceful ‚extension’ of human intelligence.The article herein presents certain medium-term prognosis, via the dynamic modelling, elements of bifurcation theory and the Xpp software.  The case study has been the object of a research contract with the business environment. 

Cold-formed Steel Sections Experimental Data Base

Thin-walled cold-formed member critical load in the coupling point of overall/local buckling modes is defined, together with critical load erosion factor (ψ). A calibration method for (ψ) using an experimental database called DATACOST is presented