The authors describe ACT-R/perceptual-motor (ACT-R/PM), an integrated theory of cognition, perception, and action that consists of the ACT-R production system and a set of perceptual-motor modules. Each module (including cognition) is essentially serial, but modules run in parallel with one another. ACT-R/PM can model simple dual tasks such as the psychological refractory period (PRP), includin...

We give new examples of discrete Schrδdinger operators with potentials taking finitely many values that have purely singular continuous spectrum. If the hull X of the potential is strictly ergodic, then the existence of just one potential x in X for which the operator has no eigenvalues implies that there is a generic set in X for which the operator has purely singular continuous spectrum. A su...

Most studies using the psychological refractory period (PRP) design suggest that dual-task performance is limited by a central bottleneck. Because subjects are usually told to emphasize Task 1, however, the bottleneck might reflect a strategic choice rather than a structural limitation. To evaluate the possibility that central operations can proceed in parallel, albeit with capacity limitations...

This paper aims at measuring reputational effects for financial institutions by examining a firm’s stock price reaction to the announcement of particular operational loss events such as internal frauds. We conduct at this purpose an event study analysis of the impact of operational loss events on the market values of banks and insurance companies, using the OpVar database (OpData dataset suppli...

This article looks to dispel the mysteries of the 'black art' of Medical Operational Planning whilst giving an overview of activity within the Medical Operational Capability area of Medical Division (Med Div) within Navy Command Headquarters (NCHQ) during a period when the Royal Naval Medical Services (RNMS) have been preparing and reconfiguring medical capability for the future contingent batt...

For over a decade, empirical studies examining organizational performance of IT investment have been far from conclusive. An issue that has led to the ongoing debate is inadequate methodology applied in measuring IT values. The traditional measures have been focused on financial ones such as return on investment and return on sales. Researchers therefore suggested the need to use more non-finan...

Nowadays, utilization of renewable energies for satisfying electricity demand has received more interest, and renewable electricity generation has been growing in the world. This study addresses the operational planning of a renewable electricity supply chain over a multi-period planning horizon. The purpose of this study is to maximize total profit and to optimize the operational decisions rel...

Traditional inventory models focus on operational decisions. In this research, we propose a general framework for incorporating financial states of an organization in multi-period inventory models with lost sales. This approach differs from the traditional ones in that operational decisions are correlated with and constrained by financial flows of the firm. We study the borrowing and and lendin...