Structural optimisation problem in support to building retrofitting decision

Various analysis methods, either linear elastic or non-linear, static or dynamic, are available for the performance analysis of existing buildings. Despite its advantages, it must be admitted that non-linear time history analysis can frequently become overly complex and impractical for general use as a first assessment. Simplified models, as the Capacity Spectrum Method, are frequently not able to accurately assess irregular structures. Considering these limitations, it is proposed and evaluated a simplified MDOF non-linear dynamic model, accounting for non-linear storey behaviour and storey damping. Based on the MDOF non-linear dynamic model, were developed optimization algorithms for the redesign of existing non-seismically designed structures. The optimization procedure searches for the optimum storey strengthening distribution (strength, stiffness or damping) in order to meet specific performance requirements, in terms of maximum inter-storey drift for a given seismic demand level. Numerical examples are presented in order to illustrate the capability of methodology

Experimental assessment and retrofit of full-scale models of existing RC frames

PSD tests on two full-scale models of existing non-seismic resisting RC frame structures are described. The testing program covered several aspects, namely assessment of seismic performance of existing frames without and with infill panels, retrofitting of the bare frame using Selective Retrofitting techniques, strengthening of the infill panels using shotcrete and retrofitting of the frame using K-bracing with shear-link dissipators. The main results from the tests are summarized and discussed and the conclusions are drawn. The tests on the bare frame have shown how vulnerable are existing structures constructed in the 60’s and the beneficial effects of infill panels were confirmed from the tests on the infilled frame. Important improvements, in terms of seismic performance, were achieved by the retrofitting of the frames. However, it was also confirmed that strengthening of the existing infill panels in poorly detailed frames may lead to dangerous ‘local’ failures, such as the shear out of the external columns

Can Brazilian Firms Survive the Chinese Challenge: Effects of Globalization on Markets, Strategies, and Performance

Purpose – The purpose of this paper is to apply the structure-conduct-performance theory and the strategic fit concept to examine the effects of globalization on markets, strategies, and performance of business-to-consumer firms in Brazil. Design/methodology/approach – The paper takes a qualitative approach to answer the research questions. Top decision makers such as president, chief executive officer, chairman of the board, vice president, and director of the companies were interviewed. The elite approach to in-depth interviewing was followed to obtain reliable information from the decision makers. Findings – Findings indicate that globalization and especially the entry of Chinese firms significantly changed market contexts in Brazil. Brazilian executives responded to changes in market contexts by shifting from production to customer orientation, building brand equity, developing new products, and differentiating offerings. Overall, marketing performance of Brazilian firms was positive, but profitability suffered. Originality/value – The study contributes to the literature by showing that globalization has changed market contexts in Brazil by developing a new form of competition in which firms from emerging economies are now competing against each other. Findings from this study can provide useful theoretical and strategic insights into the behavior and performance of firms in other emerging markets

Competitive Threats, Strategic Responses and Performance of Brazilian B2B Firms

Purpose – The economic realignment in Latin America has created two clusters, one stagnant in the north and the other growth-bound in the south. This study aims to focus on Brazil, the key player in the growth-bound southern cluster, and address three fundamental questions: how Brazilian executives in four B2B sectors (telecommunications, business equipment, steel, and transportation) viewed the internal competitive developments, how they strategically responded to these developments, and what were the marketing and financial outcomes of these strategies. Design/methodology/approach – Data were obtained by interviewing top decision makers such as president, chief executive officer, and director of the companies. Findings – Findings show that the intensity of competitive pressures due to globalization varied by sector and so did strategic responses of firms. Marketing and financial performance outcomes also varied by sectors. Originality/value – The study adds to the growing literature on competitive market developments, strategic responses and performance outcomes of firms in Brazil, an important emerging economy and the key player in the southern Latin America cluster

Vanishing ideals over graphs and even cycles

Let X be an algebraic toric set in a projective space over a finite field. We study the vanishing ideal, I(X), of X and show some useful degree bounds for a minimal set of generators of I(X). We give an explicit description of a set of generators of I(X), when X is the algebraic toric set associated to an even cycle or to a connected bipartite graph with pairwise disjoint even cycles. In this case, a fomula for the regularity of I(X) is given. We show an upper bound for this invariant, when X is associated to a (not necessarily connected) bipartite graph. The upper bound is sharp if the graph is connected. We are able to show a formula for the length of the parameterized linear code associated with any graph, in terms of the number of bipartite and non-bipartite components