Concession-making in multi-attribute auctions and multi-bilateral negotiations: Theory and experiments

Concession-making behavior is an essential process in negotiations and auctions and has critical impact on the outcomes of an exchange. In auctions, concessions relate to deciding on the next bid by bid-makers, while in negotiations they involve proposing next offers by both parties. The purpose of this paper is twofold: (1) present a theory of concessions which could be applied to both auctions and negotiations and (2) provide experimental verification of the theory. The concession model identifies nine types of concessions derived from the preference structures. The occurrence of all nine types has been confirmed in experiments. The model also identifies two concession categories which are associated with the process transparency. The theory-based assessment of the concession-making in multi-attribute auctions and multi-issue multi-bilateral negotiations allows for their comparison. To this end, two systems implemented on the Invite e-negotiation platform are used. One of the major findings suggests that auctions induce concession-making that is more likely to lead to Pareto-optimal agreements. This study also suggests that greater transparency in negotiations is likely to lead to better agreements.     

New grain formation during warm deformation of ferritic stainless steel

Microstructural evolution accompanied by localization of plastic flow was studied in compression of a ferritic stainless steel with high stacking fault energy (SFE) at 873 K (≈0.5 Tm). The structure evolution is characterized by the formation of dense dislocation walls at low strains and subsequently of microbands and their clusters at moderate strains, followed by the evolution of fragmented structure inside the clusters of microbands at high strains. The misorientations of the fragmented boundaries and the fraction of high-angle grain boundaries increase substantially with increasing strain. Finally, further straining leads to the formation of new fine grains with high-angle boundaries, which become more equiaxed than the previous fragmented structure. The mechanisms operating during such structure changes are discussed in detail.     

Effect of Liquid Hot Isostatic Pressing on Structure and Mechanical Properties of a Sand-Cast A356.02 Alloy

The effect of liquid hot isostatic pressing (LHIP) on the structure and mechanical properties of an A356.02 alloy was examined. It was shown that LHIP provides a porosity decrease from ~0.9 to 0.2 pct due to the elimination of shrinkage voids. As a result, the yield stress (YS) increases from 200 to ~230 MPa, the ultimate tensile strength (UTS) increases from ~275 to 310 MPa, the total elongation increases from ~4 to ~7.5 pct, and the fatigue strength increases from ~88 to ~140 MPa. It was found that the sequence of LHIP and homogenization annealing highly affects the hardness and variability in fatigue strength. LHIP followed by homogenization annealing provides the lowest scattering of fatigue strength and, therefore, the fabrication of the most reliable casting components.     

Effect of Co on Creep Behavior of a P911?Steel

The microstructure and creep behavior of a 3 pct Co modified P911 steel and standard P911 steel were examined. It was shown that the nanoscale M₂₃C₆ carbides and MX carbonitrides in the 3 pct Co modified P911 steel are not susceptible to significant coarsening under creep conditions. Also, coarsening simulations of M₂₃C₆ particles were performed for both steels. The rates of lath and particle coarsening in the P911 + 3 pct Co steel are remarkably lower than those in the P911. Increased stability of a tempered martensite lath structure in the 3 pct Co modified P911 steel provides enhanced creep resistance at an exceptionally high temperature of 923 K (650 °C).