We present discrete-time stochastic extremum seeking algorithms and prove their convergence using stochastic averaging theory that we recently developed. First, we provide a discrete stochastic extremum seeking algorithm for a static map, in which measurement noise is considered and an ergodic discrete-time stochastic process is used as the excitation signal. Second, for discrete-time nonlinear...

This paper presents an extension to the classical gradient-based extremum seeking control for the case when the disturbances responsible for changes in the extremum of a selected performance function are available for measurement. Based on these additional measurements, an adaptive extremum seeking disturbance feedforward is designed that approximates the unknown, static mapping between the dis...

In this paper, we present an adaptive extremum seeking control scheme for nonisothermal continuous stirred tank reactors subject to reactor temperature constraints. Only limited knowledge of the reaction kinetics is assumed with no direct measurement of the reaction mixture composition. An adaptive learning technique is introduced to construct an optimum seeking algorithm that drives the system...

In this paper we look at some of the problems in interacting with best-match retrieval systems. In particular, we examine the areas of interaction, some investigations of the complexity and breadth of interaction and attempts to categorise user's information seeking behaviour. We suggest that one of the diiculties of traditional IR systems in supporting information seeking is the way the inform...

This paper outlines a broad research agenda aimed at examining the manner in which individual differences in information seeking behavior interact with the search task to affect search outcomes. As part of this agenda, we describe specific experimentation that will assess the impact of both Need for Cognition (the tendency to elaborate upon, structure and evaluate information) and Selfand Other...

This paper presents an argument that information systems may support deeper engagement between readers and the text by realizing the capacity for readers to take more active roles while seeking information. Information systems could support collaborative information seeking by displaying shared annotations. Subsequent readers would be able to leverage the semantic information encoded within the...

In various work domains, the collaborative performance of a work-task by a team can lead to a shared information need required to fulfill this task. Many empirical studies identified collaborative information seeking and searching (IS&S) as everyday work patterns in order to solve a shared information need and to benefit from the diverse expertise and experience of the team members. This paper ...

This article examines the information seeking behavior and meaningmaking in virtual play spaces by employing the example of one such space. The researcher examines the means by which game players get the information needed to succeed in a game through the lens of everyday life information seeking, and how they make meanings in the play space through the lens of the dramaturgical approach. While...

When searching for information, people often seek help from others. However, while people can benefit from communicating with others, they can usually satisfy their information needs, to some degree, without help. Because establishing explicit collaborations is often seen as onerous, there are many missed opportunities where shared experiences could save time and effort. In this work, we propos...

In this paper, we evaluate query term suggestion in the context of academic professional search. Our overall goal is to support scientists in their information seeking tasks. We set up an interactive search system in which terms are extracted from clicked documents and suggested to the user before every query specification step. We evaluated our method with the iSearch collection of academic in...