On the Informational Comparison of Qualitative Fuzzy Measures

International audienceFuzzy measures or capacities are the most general representation of uncertainty functions. However, this general class has been little explored from the point of view of its information content, when degrees of uncertainty are not supposed to be numerical, and belong to a finite qualitative scale, except in the case of possibility or necessity measures. The thrust of the paper is to define an ordering relation on the set of qualitative capacities expressing the idea that one is more informative than another, in agreement with the possibilistic notion of relative specificity. To this aim, we show that the class of qualitative capacities can be partitioned into equivalence classes of functions containing the same amount of information. They only differ by the underlying epistemic attitude such as pessimism or optimism. A meaningful information ordering between capacities can be defined on the basis of the most pessimistic (resp. optimistic) representatives of their equivalence classes. It is shown that, while qualitative capacities bear strong similarities to belief functions, such an analogy can be misleading when it comes to information content

European Flight Restrictions May Inhibit International Propagation of Ebola

The rise of aviation as the dominant form of international transportation has increased the potential for the spread of infectious diseases. The 2014 West African Ebola Outbreak is no exception, with localized outbreaks in multiple countries caused by infected individuals traveling by plane. To inhibit the spread of Ebola to the United States it has been suggested that airlines cancel direct inbound flights from the affected region. To examine the effects of this approach, we developed and analyzed an agent-based metapopulation network model to simulate the international flight-based spread of Ebola. A metapopulation network consisting of 3,052 subpopulations connected by 83,295 flights was developed to simulate the transportation and infection of individuals in discrete timesteps of 30 minutes. To simulate the transmission dynamics of Ebola within subpopulations, airports, and flights, we constructed an SEIR model in which individuals are classified as either susceptible, exposed, infectious, or removed. The spread of Ebola was simulated using an R0 of 2.1, as estimated for the 2014 West African Ebola outbreak, and extrapolated to scenarios of unilateral flight restrictions. We tested situations in which the United States, the European Union, or other African nations refused inbound flights. We found that flight restrictions can decrease the number of subpopulations with infectious or exposed individuals, with European-bound flight restrictions decreasing the spread of Ebola by as much as 80%. While flight restrictions may be politically and economically infeasible, our model suggests that the implementation of flight restrictions on European-bound flights may effectively mitigate the international spread of Ebola

On the Convergence of Fuzzy Sets and the Completeness of the Space of Fuzzy Sets

AbstractIn this article, we first introduce several convergence concepts of fuzzy sets. Then we construct an embedding of the space of fuzzy sets in a normed linear space. We prove that the space of fuzzy sets is a complete metric space under the embedding. This framework enables us to study the calculus of fuzzy functions

Ordered Weighted Average Based Fuzzy Rough Sets

Traditionally, membership to the fuzzy-rough lower, resp. upper approximation is determined by looking only at the worst, resp. best performing object. Consequently, when applied to data analysis problems, these approximations are sensitive to noisy and/or outlying samples. In this paper, we advocate a mitigated approach, in which membership to the lower and upper approximation is determined by means of an aggregation process using ordered weighted average operators. In comparison to the previously introduced vaguely quantified rough set model, which is based on a similar rationale, our proposal has the advantage that the approximations are monotonous w.r.t. the used fuzzy indiscernibility relation. Initial experiments involving a feature selection application confirm the potential of the OWA-based model

Historic Changes (1941–2008) In Side Channel And Backwater Habitats On An Unchannelized Reach Of The Missouri River

Flow regulation has had pervasive effects on aquatic ecosystems within the world’s large rivers. While channelization on the lower Missouri River has led to major changes in the river and its floodplain, including the loss of shallow water habitats, effects of upstream dams on unchannelized reaches on the Missouri have not been formally assessed. We quantified changes in the number and size of off-channel habitats, specifically backwaters and side channels, on the 95-km unchannelized reach of the Missouri below Gavins Point Dam (Yankton, South Dakota) using historical (1941, 1983–1985, 2008) aerial imagery. Total and mean areas of side channels declined by 77% and 37% and total and mean length decreased by 79% and 42% from 1941 to 2008. Total area of backwaters increased by 40% from 1941 to 2008, whereas mean area decreased by 36%. Our findings suggest that sharp declines in the area and length of side channels have occurred on this unchannelized remnant reach of the Missouri River, with likely significant impacts on aquatic ecosystem processes

The Relationship between Physical Growth and Infant Behavioral Development in Rural Guatemala

The present study investigated the relationship between a number of anthropometric indices and behavioral development during the first 2 years of life in rural Guatemala. Length and weight were the indices most strongly correlated with behavioral development. If the effect of the infant\u27s length and weight was statistically controlled for, none of the other anthropometric variables explained a significant proportion of the variance in behavioral development. Con- trolling for length (or weight) assessed at the same age as the behavioral assessment, length (or weight) for younger ages was not significantly correlated with behavioral development. Changes in length or weight over time were correlated with changes in behavioral performance. We were unable to explain the association between physical growth and behavioral development by a number of variables including gestational age, nutrient intake, prevalence of disease, and familial characteristics

Incomplete conjunctive information

AbstractMany information systems capable of handling incomplete or fuzzy information manipulate objects with single-valued attributes. Information is then said to be disjunctive. Information is said to be conjunctive when pertaining to many-valued attributes. While a piece of incomplete disjunctive information is easily represented by means of a set of mutually exclusive possible values, modeling incomplete conjunctive information theoretically leads to consider families of sets, since attributes are then set-valued under complete information. Some proposals are made in order to efficiently and rigorously represent incomplete conjunctive information, and deal with query evaluation, especially in the case where only upper and/or lower bounds of the set of values of a many-valued attribute are known. Applications of this approach can be expected for the processing of time intervals, as well as spatial reasoning, among other topics, in knowledge base management