We present a family of epidemic algorithms for maintaining replicated database systems. The algorithms are based on the causal delivery of log records where each record corresponds to one transaction instead of one operation. The first algorithm in this family is a pessimistic protocol that ensures serializability and guarantees strict executions. Since we expect the epidemic algorithms to be u...

Linguistic negation processing is a challenging problem studied by a large number of researchers from different communities, i.e. logic, linguistics, etc. We are interested in finding the positive interpretations of a negative sentence represented as ”x is not A”. In this paper, we do not focus on the single set of translations but on two approximation sets. The first one called pessimistic cor...

The problem of computing the strategy to commit to has been widely investigated in the scientific literature for the case where a single follower is present. In the multi-follower setting though, results are only sporadic. In this paper, we address the multi-follower case for normal-form games, assuming that, after observing the leader’s commitment, the followers play pure strategies and reach ...

The designs of software transactional memory (STM) algorithms to date have been optimistic: transactions that run into inconsistencies abort and retry. The common view is that this optimistic approach gives significant performance benefits, and yet we know that it also results in complex programming, limitations on what can be executed within a transaction, and difficult debugging. This is a bu...

This paper deals with approaches to the granular space reductions in the variable precision multigranulation rough set model. The main objective of this study is to extend four kinds of the granular space reductions called a tolerance relations optimistic multigranulation  ower approximation distribution reduction, a tolerance relations optimistic multigranulation  upper approximation distrib...

In the paper a new approach to goal programming is presented: the robust approach, applied so far to a single-objective linear programming. It is a ”pessimistic” approach, meant to find a solution which will be reasonably good even in a bad case, but it is based on the assumption that almost never everything goes bad the decision maker can control and simulate the pessimistic aspect of the deci...

We consider the extension of non-monotonic preference logic with the distinction between controllable (or endogenous) and uncontrollable (or exogenous) variables, which can be used for example in agent decision making and deliberation. We assume that the agent is optimistic about its own controllables and pessimistic about its uncontrollables, and we study ways to merge these two distinct dimen...

Recent developments in the theory of choice under uncertainty and risk yield a pessimistic decision theory that replaces the classical expected utility criterion with a Choquet expectation that accentuates the likelihood of the least favorable outcomes. A parallel theory has recently emerged in the literature on risk assessment. It is shown that a general form of pessimistic portfolio optimizat...

Seligman's theory of causal attribution predicts that patients with a pessimistic explanatory style will have less favourable health outcomes. We identified 702 patients who had undergone 894 primary total knee replacements between 1993 and 2005, who responded to follow-up surveys at two (n = 783 knee replacements) and/or five years (n = 443 knee replacements) and had also completed the Minneso...

This paper uses a natural experiment to estimate the causal impact of low-casualty terrorist attacks on pessimistic beliefs in Africa. Distinct from fear, pessimism has been found hinder optimal economic decisions and well-being. By comparing survey responses people interviewed same area immediately before after attack, we find that terrorism increases about future living conditions by 11 perce...