Rapid omnidirectional vision acquisition using an intelligent linear scanning technique

Many computer vision applications can benefit from omnidirectional vision sensing, rather than depending solely on conventional cameras that have constrained fields of view. For example, mobile robots often require a full 360 view of their environment in order to perform navigational tasks such identifying landmarks, localizing within the environment, and determining free paths in which to move. There has been much research interest in omnidirectional vision in the past decade and many techniques have been developed. These techniques include: (i) catadioptric methods which can provide rapid image acquisition, but lack image resolution; and (ii) mosaicing and linear scanning techniques which have high image resolution but typically have slow image acquisition speed. In this paper, we introduce a novel linear scanning panoramic vision system that can acquire panoramic images quickly with little loss of image resolution. The system makes use of a fast line-scan camera, instead of a slower, conventional area-scan camera. In addition, a unique coarse-to-fine panoramic imaging technique has been developed that is based on smart sensing principles. Using the active vision paradigm, we control the motion of the rotating camera using feedback from the images. This results in high acquisition speeds and proportionally low storage requirements. Experimentation has been carried out, and results are given. Correspondence to: M.J. Barth (e-mail: barth@ee.ucr.edu)     

Meta-Interpretation and Hypertext Fiction: A Critical Response

Traditional discourses upon literature havebeen predicated upon the ability to refer to atext that others may consult (Landow, 1994,p. 33). Texts that involve elements of feedbackand non-trivial decision-making on the part ofthe reader (Aarseth, 1997, p. 1) therefore presenta challenge to readers and critics alike. Sincea persuasive case has been made against acritical method that sets out to ``identify thetask of interpretation as a task of territorialexploration and territorial mastery' (Aarseth,p. 87), this paper proposes the use of readers inan empirically based approach to hypertextfiction. Meta-interpretation, a method thatcombines individual responses to a text,reading logs, screen recordings and limitedqualitative/quantitative analysis, and criticalinterpretation is outlined. By analysingreaders' responses it is possible to suggestboth the ways that textual elements may haveinfluenced or determined readers' choices andthe ways that readers' choices ``configure' thetext. The method thus addresses Espen Aarseth'sconcerns and illuminates interesting featuresof interactive processes in fictionalenvironments. The paper is divided into twoparts: the first part sketches outmeta-interpretation through consideration ofthe main problems confronting the literarycritic; the second part describes readingresearch aimed at generating data for theliterary critic.     

Application of Carbohydrases in Extracting Protein from Rice Bran

Enzymatic pretreatments of rice bran, using commercial carbohydrases to improve nitrogen extractability, were investigated. The pretreatment used a response surface method which included the variations in concentration of Viscozyme L (0–120 FBG unit) and Celluclast 1.5L (0–360 NC unit), time of incubation (1–5 h) and pH (3·8–5·4). The experiments were conducted at two different temperatures, 40 and 50°C. At 40°C, the maximum nitrogen extraction predicted by the model was obtained when the Viscozyme–Celluclast mixture at pH 3·8 with incubation time of 5 h was applied, giving an extracted N of 51%. At the process temperature of 50°C, the model predicted that the use of Viscozyme alone, under similar conditions, would have a most significant effect in increasing the efficacy of the nitrogen extraction, producing a 57% extracted N. This enzymatic pretreatment method improved the nitrogen extractability of rice bran at the neutral pH. © 1997 SCI.     

A Novel and Rapid Method for the Partial Fractionation of Starch using 1-Butanol in the Presence of Thiocyanate

An effective separation of amylose from amylopectin in wheat and corn starches has been achieved by the novel use of potassium thiocyanate (KSCN) as a dispersant prior to precipitation of the amylose as butanol complex. Amylopectin remaining in solution was recovered by precipitation with ethanol. Fractions were assayed colorimetrically for amylose using iodine. Various conditions for the optimal use of KSCN were evaluated, including the concentration required for gelatinisation of the starch, the concentration of starch and the ratio of KSCN to starch. Optimal results were obtained with amounts of KSCN equal to the weight of starch used. The process requires relatively few steps, is rapid and results in good yields of products which do not appear to be significantly degraded.     

The use of verbal protocols to understand and design skill-based tasks

A study of the effects of increased levels of automation on the human operator illustrates the use of a computer-based approach to the use of verbal protocols as data in skill-based tasks, such as printed circuit board inspection. Subjects provided very detailed protocols at four automation levels, as well as generating performance and preference data. Although only one performance measure and one preference measure gave useful results, the use of verbal protocols provided many insights into the system-human interaction. Supplementing traditional performance measures with verbal protocols appears to be an appropriate strategy, even when the task is primarily at the skill level. © 1998 John Wiley & Sons, Inc.     

Holes in Starch Granules: Confocal,SEM and Light Microscopy Studies of Starch Granule Structure

Following an initial observation of putative holes within potato starch granules during observation in a medium with the same refractive index, the internal architecture of starch granules has been investigated using confocal, scanning electron and light microscopy. These complimentary microscopy techniques confirmed the existence of holes at the hilum of potato, rice and wheat starch granules. Observations were made with minimal sample preparation to avoid the generation of artifactual holes. Using image analysis we have quantitatively measured the occurrence and the size distribution of holes and linked their appearance to the drying of the granule.     

Model catalyst studies with single crystals and epitaxial thin oxide films

The paper describes recent results from our relatively new program to perform detailed studies of the catalytic properties of metal-oxide materials; in particular, to effect a determination of the active catalytic site(s) and the mechanism for reactions over this especially important class of heterogeneous catalysts. Issues of structure-sensitivity, poisoning and promotion, and competing reaction mechanisms are critical questions that need to be addressed in a detailed manner for catalysis by oxides. As just one important example, both surface (Langmui–Hinshelwood) and direct (Eley–Rideal) reaction mechanisms have been proposed for the selective catalytic reduction (SCR) reaction of nitrogen oxides (NO_x) over vanadia/titania catalysts. For this program, we are using a number of unique, state-of-the-art capabilities available in the Environmental Molecular Sciences Laboratory (EMSL) at Pacific Northwest National Laboratory; for example, the first molecular beam epitaxy (MBE) system dedicated to the growth of model metal-oxide films, and a unique moderate-pressure catalytic reactor/surface science apparatus. We describe the growth, characterization, and water adsorption properties of a thin Fe₃O₄(0 0 1) film grown on a lattice-matched MgO(0 0 1) substrate. Because our moderate pressure catalysis studies are preliminary at this point, we instead describe our previous results on the CO oxidation reaction over a Ru(0 0 0 1) model catalyst to demonstrate the utility of the experimental approach. We specifically discuss the possibility that this reaction occurs by an Eley–Rideal mechanism.     

Prospects for detecting metal–adsorbate vibrations by sum‐frequency spectroscopy

Sum‐frequency spectroscopy (SFS) was used in an attempt to detect the platinum–carbon vibration of CO adsorbed on Pt(111). The international free‐electron laser FELIX at the FOM Institute, Rijnhuizen, provided the required tunable far‐infrared (19–23 μm) source, while complementary measurements in the C–O stretch region (4.7–5.1 μm) were performed at the University of Oxford with a conventional nanosecond laser system. Ordered Pt(111) surfaces were prepared by the H₂/O₂ flame annealing approach and CO monolayers were produced by exposure of the Pt crystal to gaseous CO in a flow reactor. The monolayers were characterized by sum‐frequency (SF) measurements of the v _C-O vibrational frequency. The CO adsorbed primarily in the terminal (atop) configuration, with a v _C-O frequency of around 2078 cm⁻¹. In the far‐IR region, the non‐resonant background from the Pt substrate could readily be detected by SFS, but there was no evidence for the v _Pt-CO mode. Direct laser‐induced desorption and thermal desorption of CO are unlikely under the experimental conditions. It is therefore probable that the intrinsic cross‐section of the Pt–CO mode is too low for easy detection by SFS. The implications for the use of SFS to detect metal–adsorbate vibrational modes are discussed in light of these findings. This revised version was published online in July 2006 with corrections to the Cover Date.     

Mechanical properties of CRETE,a polyurethane foam

The room-temperature mechanical properties of a closed-cell, polyurethane encapsulant foam were measured as a function of foam density. Over the range of densities examined, the modulus could be described by a power-law relationship with respect to density. This power-law relationship was the same for both tension and compression testing. The basis for this power-law relationship is explained in terms of the elastic compliance of the cellular structure of the foam using a simple geometric model put forth by Gibson and Ashby. The elastic collapse stress, a property relevant to compression testing, also is found to exhibit a power-law relationship with respect to density. The density dependence of this property is also found in the work of Gibson and Ashby and is explained in terms of the Euler buckling of the struts that comprise the cellular structure. Energy absorption during deformation is also reported for both tension and compression testing. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 1045–1055, 1998