DePaul University

About: DePaul University is a education organization based out in Chicago, Illinois, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 5658 authors who have published 11562 publications receiving 295257 citations.

Complexity of some geometric and topological problems

Abstract: We show that recognizing intersection graphs of convex sets has the same complexity as deciding truth in the existential theory of the reals. Comparing this to similar results on the rectilinear crossing number and intersection graphs of line segments, we argue that there is a need to recognize this level of complexity as its own class.

Recommender Systems: An Overview

Abstract: Recommender systems are tools for interacting with large and complex information spaces. They provide a personalized view of such spaces, prioritizing items likely to be of interest to the user. The field, christened in 1995, has grown enormously in the variety of problems addressed and techniques employed, as well as in its practical applications. Recommender systems research has incorporated a wide variety of artificial intelligence techniques including machine learning, data mining, user modeling, case-based reasoning, and constraint satisfaction, among others. Personalized recommendations are an important part of many on-line e-commerce applications such as Amazon.com, Netflix, and Pandora. This wealth of practical application experience has provided inspiration to researchers to extend the reach of recommender systems into new and challenging areas. The purpose of this special issue is to take stock of the current landscape of recommender systems research and identify directions the field is now taking. This article provides an overview of the current state of the field and introduces the various articles in the special issue.

Visual Input to the Efferent Control System of a Fly's "Gyroscope"

Abstract: Dipterous insects (the true flies) have a sophisticated pair of equilibrium organs called halteres that evolved from hind wings. The halteres are sensitive to Coriolis forces that result from angular rotations of the body and mediate corrective reflexes during flight. Like the aerodynamically functional fore wings, the halteres beat during flight and are equipped with their own set of control muscles. It is shown that motoneurons innervating muscles of the haltere receive strong excitatory input from directionally sensitive visual interneurons. Visually guided flight maneuvers of flies may be mediated in part by efferent modulation of hard-wired equilibrium reflexes.

Beyond mood and social judgment: Mood incongruent recall and mood regulation

Abstract: Two studies explored mood incongruent recall and the self-regulation of moods. In Study I, subjects were put into sad or happy moods before recalling a mood incongruent event. Subjects engaged in one of three types of recall: effortless, effortful, or no recall. Results showed that the greatest change in mood occurred for effortful recall. In Study 2 subjects were again put into a particular mood and were asked to recall anything they wanted — either at the beginning or the end of a class session. In general, subjects chose to remember mood congruent events; however, subjects in negative moods recalled more positive events when they performed the task at the beginning of class. Implications of the results for issues of mood regulation and mood congruent judgment are discussed.

To Blame or Not to Blame: Analysts' Reactions to External Explanations for Poor Financial Performance

Abstract: Managers often provide self-serving disclosures that blame poor financial performance on temporary, external factors. Results of an experiment conducted with 124 financial analysts suggest that when analysts perceive such disclosures as plausible, they provide higher earnings forecasts and stock valuations than if the explanation had not been provided. However, we also show that these disclosures can backfire if analysts find them implausible. Specifically, implausible external explanations for poor performance lead analysts to provide lower earnings forecasts and assess a higher cost of capital than if the explanation had not been provided.