The DIPPER architecture is a collection of software agents for prototyping spoken dialogue systems. Implemented on top of the Open Agent Architecture (OAA), it comprises agents for speech input and output, dialogue management, and further supporting agents. We define a formal syntax and semantics for the DIPPER information state update language. The language is independent of particular program...

We assessed whether sign-tracking developed along with goal-tracking in a Pavlovian drug discrimination task. Rats had nicotine sessions intermixed with saline sessions. For nicotine sessions, 15-s illumination of a light near (Experiment 1) or far (Experiment 2) from the dipper receptacle was followed by sucrose. Saline sessions were similar to nicotine sessions except sucrose was withheld. Re...

We measured the just-noticeable difference (JND) in orientation variance between two textures (Figure 1) as we varied the baseline (pedestal) variance present in both textures. JND's first fell as pedestal variance increased and then rose, producing a 'dipper' function similar to those previously reported for contrast, blur, and orientation-contrast discriminations. A dipper function (both faci...

BACKGROUND AND OBJECTIVES The aim of this study was to evaluate the effects of an L- and T-type calcium channel blocker (CCB) on 24-hour systolic blood pressure (24-hour SBP) and heart rate (24-hour HR) profiles in essential hypertensive patients. SUBJECTS AND METHODS Thirty-seven consecutive patients were enrolled in this study. The 24-hour SBP and HR were recorded before and after treatment...

Models of the dipper effect seen in contrast discrimination experiments predict that small amounts of noise should facilitate detection of a subthreshold sinusoidal grating. Although facilitation of chromatic sine waves has been measured with chromatic or luminance noise, a facilitory effect of luminance sinusoidal gratings has not been measured, most likely because the stimulus characteristics...

Patients with resistant hypertension present high prevalence of a non-dipper blood pressure pattern. Recent results indicate that non-dipping is related partly to the absence of 24-hour therapeutic coverage in patients treated with single morning doses. Accordingly, we investigated the impact of treatment time on the blood pressure pattern in 700 patients with resistant hypertension on the basi...

Dipper-shaped curves often accurately depict the relationship between a baseline, or "pedestal," magnitude and a just noticeable difference in it. This tutorial traces the 45-year history of the dipper function in auditory and visual psychophysics, focusing on when they happen and why. Popular theories of both positive and negative masking (i.e., the "handle" and "dip," respectively) are descri...