Fair Resource Allocation in a Volatile Marketplace

2021 ◽  
Author(s):  
MohammadHossein Bateni ◽  
Yiwei Chen ◽  
Dragos Florin Ciocan ◽  
Vahab Mirrokni

In settings where a platform must allocate finite supplies of goods to buyers, balancing overall platform revenues with the fairness of the individual allocations to platform participants is paramount to the well-functioning of the platform. This is made even more difficult by the fact that the supply of goods is in practice stochastic and difficult to forecast, such as in the case of online ad allocation, where the platform manages a supply of impressions that varies over time. In this paper, we design a fair allocation scheme that works in the presence of supply uncertainty. Algorithmically, the scheme repeatedly solves for Fisher market equilibria in a model predictive control fashion and is proved to admit constant factor guarantees versus the offline optimal. In addition, the scheme is tested on a sequence of real ad datasets, showing strong empirical performance.

2014 ◽  
Vol 1049-1050 ◽  
pp. 996-999
Author(s):  
Fu Rong Liu ◽  
Shuang Qing Tang ◽  
Cong Ping Chen

The dynamic positioning (DP) vessel maintains its position and heading by active thrusters. For safety reasons, DP vessels are typically designed with redundancy thrusters more than needed for motion control. Optimization theories are useful in finding thrust allocation solutions that minimize fuel consumption and reduce “wear and tear” on a thruster. But several challenges exist such as uncertain thruster model, thruster dynamics characters and the individual limitations of the thrusters. In this paper, a dynamic thrust allocation scheme is presented based on model predictive control (MPC) that directly takes thrusters with dynamics characters and various constraints into account. It is shown in simulations that the MPC dynamic thrust allocation scheme performs better in comparison with an existing static allocation method. Its main advantage is the ability to handle thruster dynamics characters and various constraints.


1999 ◽  
Vol 4 (4) ◽  
pp. 205-218 ◽  
Author(s):  
David Magnusson

A description of two cases from my time as a school psychologist in the middle of the 1950s forms the background to the following question: Has anything important happened since then in psychological research to help us to a better understanding of how and why individuals think, feel, act, and react as they do in real life and how they develop over time? The studies serve as a background for some general propositions about the nature of the phenomena that concerns us in developmental research, for a summary description of the developments in psychological research over the last 40 years as I see them, and for some suggestions about future directions.


2013 ◽  
Vol 4 (2) ◽  
pp. 151-156 ◽  
Author(s):  
G. Kozma ◽  
E. Molnár ◽  
K. Czimre ◽  
J. Pénzes

Abstract In our days, energy issues belong to the most important problems facing the Earth and the solution may be expected partly from decreasing the amount of the energy used and partly from the increased utilisation of renewable energy resources. A substantial part of energy consumption is related to buildings and includes, inter alia, the use for cooling/heating, lighting and cooking purposes. In the view of the above, special attention has been paid to minimising the energy consumption of buildings since the late 1980s. Within the framework of that, the passive house was created, a building in which the thermal comfort can be achieved solely by postheating or postcooling of the fresh air mass without a need for recirculated air. The aim of the paper is to study the changes in the construction of passive houses over time. In addition, the differences between the geographical locations and the observable peculiarities with regard to the individual building types are also presented.


2020 ◽  
Author(s):  
Christopher James Hopwood ◽  
Ted Schwaba ◽  
Wiebke Bleidorn

Personal concerns about climate change and the environment are a powerful motivator of sustainable behavior. People’s level of concern varies as a function of a variety of social and individual factors. Using data from 58,748 participants from a nationally representative German sample, we tested preregistered hypotheses about factors that impact concerns about the environment over time. We found that environmental concerns increased modestly from 2009-2017 in the German population. However, individuals in middle adulthood tended to be more concerned and showed more consistent increases in concern over time than younger or older people. Consistent with previous research, Big Five personality traits were correlated with environmental concerns. We present novel evidence that increases in concern were related to increases in the personality traits neuroticism and openness to experience. Indeed, changes in openness explained roughly 50% of the variance in changes in environmental concerns. These findings highlight the importance of understanding the individual level factors associated with changes in environmental concerns over time, towards the promotion of more sustainable behavior at the individual level.


2004 ◽  
Vol 79 (3) ◽  
pp. 645-665 ◽  
Author(s):  
Kevin C. W. Chen ◽  
Hongqi Yuan

From 1996 to 1998, listed companies in China were required to achieve a minimum return on equity (ROE) of 10 percent in each of the previous three years before they could apply for permission to issue additional shares. As a result of this rule, there was a heavy concentration of ROEs in the area just above 10 percent. We show that the Chinese regulators appear to have scrutinized firms using excess amounts of nonoperating income to reach the 10 percent hurdle. In addition, their ability to do so seems to have improved over time, which allows them to be better able to identify firms that subsequently performed better. However, many firms were still able to gain rights issue approval through excess nonoperating income. We show that these firms subsequently underperformed other approved firms that did not use the same practice, indicating that the Chinese regulators' objective of guiding capital resources toward the well-performing sectors is partially compromised by earnings management.


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