Subjects in a darkroom saw an array of five phosphorescent objects on a circular table and, after a short delay, indicated which object had been moved. During the delay the subject, the table or a phosphorescent landmark external to the array was moved (a rotation about the centre of the table) either alone or together. The subject then had to indicate which one of the five objects had been mov...

introduction central vein catheterization (cvc) is an important procedure for emergency departments (ed). despite the existence of ultrasonography (us) devices in every ed, cvc was accomplished by anatomical landmarks in many eds in iran. objective this study was designed for the evaluation of us-guided cvcs, anatomical landmark cvcs, and the promotion of us-guided cvc in iran. methods and mate...

An automatic mechanism that gives verbal navigation instructions to pedestrians in situ needs to take into account a number of factors. Besides giving the instruction at the right time and place, the information needs to be as unambiguous as possible for the user to both choose the correct path and be confident in doing so. Humans make extensive use of landmarks when describing the way to other...

This paper concerns the application of techniques from estimation theory to the problem of navigation and perception for a mobile robot. After a brief introduction, a hierarchical architecture is presented for the design of a mobile robot navigation system. The control system for a mobile robot is found to decompose naturally into a hierarchy of control loops, where the levels are defined by th...

This paper contributes to the literature on divided government and legislative productivity. We begin by reexamining Mayhew's data on landmark enactments. We show that Mayhew's claim that divided government does not affect legislative productivity is a consequence of aggregating time series that exhibit different behavior. We then extend Mayhew's analysis by broadening the concept of significan...

The problem of continuous position availability is one of the most important issues connected with the human activity at sea. Because the availability of satellite navigational systems can be limited in some cases, e.g. during military operations, one has to consider additional methods of acquiring information about the ship’s position. In this paper one of these methods is presented, which is ...