Constructing the Voronoi diagram of a set of line segments in parallel

In this paper we give a parallel algorithm for constructing the Voronoi diagram of a polygonal scene, i.e., a set of line segments in the plane such that no two segments intersect except possibly at their endpoints. Our algorithm runs inO(log² n) time usingO(n) processors in the CREW PRAM model.The research of M. T. Goodrich was supported by NSF under Grants CCR-8810568 and CCR-9003299 and by NSF/DARPA under Grant CCR-8908092. C. K. Yap's research was supported in part by NSF Grants DCR-8401898 and CCR-9002819.     

Continuous background monitoring of plant performance utilizing asingle-chip microcomputer and PRTN sequences

The authors demonstrate a method suitable for a single-chip microcomputer or VLSI implementation that provides continuous real-time background monitoring of linear electromechanical systems. In this implementation method, pseudorandom noise is generated and digitized with a single-chip microcomputer and utilized to observe shifts in plant performance by monitoring the impulse response. A Butterworth filter was chosen to simulate the electromechanical system for ease and convenience of transfer function modification during testing. The feasibility of monitoring and detecting shifts in plant performance using pseudorandom noise in the background mode in real time while the plant continues to carry out routine control was demonstrated experimentally. Guidelines are provided for selecting the pseudorandom noise amplitude and the analog/digital quantization level. Pseudorandom trinary noise was demonstrated to be superior to pseudorandom binary noise     

Performance of ULV formulations (Pesguard 102/Vectobac 12AS) against three mosquito species

To study the effects of percutaneous ethanol injection therapy on livers, we investigated necrotic changes after ethanol injection and fibrotic changes during the repair process in cirrhotic livers in comparison with normal livers. Male rats were treated with oral doses of 3'-methyl-4-dimethylaminoazobenzene and thioacetamide to produce liver cirrhosis. Both control animals and cirrhotic animals were injected with 0.2 ml of absolute ethanol into livers. Histological samples were cut serially, and the maximum areas of necrosis and fibrosis were measured until 28 days after the injection. Although the maximum area of necrosis was not different between cirrhotic livers and control livers, the average fibrotic ratio [(maximum fibrotic area/maximum necrotic area + maximum fibrotic area) x 100] was 64% in control livers (n = 9) and 40% in cirrhotic livers (n = 9; p < 0.05). The fibrotic repair process after ethanol injection seems to be impaired in cirrhotic livers as compared with normal livers.     

An evaluation of two hypotheses concerning the dynamics of cognitive impulsivity: Anxiety-over-errors or anxiety-over-competence?

To test the appropriateness of the anxiety-over-errors and the anxiety-over-competence hypotheses in explaining reflective and impulsive behavior, 85 8–11 yr olds were classified as reflective or impulsive on the basis of their performance on 1 form of the Matching Familiar Figures Test (MFFT). Half of each cognitive style group was randomly assigned to a failure or control group. Ss in the failure group were given failure feedback concerning their performance on the 1st 10 items of an alternate form of the MFFT and were then tested on the 2nd 10 items. Control Ss were given a short rest period between the 2 10-item test administrations. All Ss rated their expectancy of success and completed the Test Anxiety Scale for Children. Teacher ratings of the children's reflection–impulsivity, confidence, and concern over errors were also obtained. Results support the anxiety-over-errors hypothesis: The impulsives in the failure group showed a significant decrease in errors from pre- to posttest, whereas controls did not differ in this respect. The reflectives in the failure group did not differ from those in the control group in their pre–post error rates. MFFT performance measures were significantly correlated with teacher ratings of concern over errors but not with confidence ratings. It is concluded that impulsive behavior may stem from a lack of motivation to perform well. (29 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Tuberculous pseudotumor causing biliary obstruction. Report of a case with diagnosis by fine needle aspiration biopsy and bile cytology

Hepatobiliary tuberculosis is a rare but distinct clinical entity. We report an unusual case of biliary tract obstruction due to localized hepatic tuberculosis with periportal tuberculous adenitis. The lesion mimicked a malignancy clinically and radiologically. Fine needle aspiration biopsy revealed granulomas, epithelioid histiocytes and Langhans' giant cells. The cytodiagnosis was confirmed by identification of acid-fast bacilli in the bile cytology and isolation of Mycobacterium tuberculosis by culture. The patient responded to antituberculosis therapy. The usefulness of bile cytology in the diagnostic management of biliary tract obstruction is illustrated.     

Parallel triangulation of a polygon in two calls to the trapezoidal map

We give a parallel method for triangulating a simple polygon by two (parallel) calls to the trapezoidal map computation. The method is simpler and more elegant than previous methods. Along the way we obtain an interesting partition of one-sided monotone polygons. Using the best-known trapezoidal map algorithm, ours run in timeO(logn) usingO(n) CREW PRAM processors.This research was supported by NSF Grants No. DCR-84-01898 and No. DCR-84-01633, and ONR Contract N00014-85-K-0046.     

Minimum area circumscribing Polygons

We show that the smallestk-gon circumscribing a convexn-gon can be computed inO(n ² logn logk) time.     

Image focus measure based on Chebyshev moments

A new measure of image focus based on the discrete orthogonal Chebyshev moments is introduced. The low- and high-spatial-frequency components of an image can be represented as the low- and high-order Chebyshev moments, respectively. The focus measure is defined as the ratio of the norm of the high-order moments to that of low-order moments. It is shown that the focus measure is monotonic and unimodal with respect to image blurring. Additionally, it is invariant to contrast changes due to the differences in the intensities of illumination. The focus measure is tested for its discriminating power of images blurred to various degrees. Noise studies show that the focus measure is robust under Gaussian and salt-and-pepper noise. The performance of the proposed focus measure is compared with the existing focus measures.     

Surface characteristics of tooth-colored restoratives polished utilizing different polishing systems

With more than 2000 wound care products on the market, choosing an appropriate dressing for the geriatric patient can prove to be a difficult task. Age-related changes in skin structure and decreased resistance to noxious stimuli in the environment place the elderly patient at higher risk for wound complications. Understanding the principles of moist wound healing and how dressing materials can be used to promote healing outcomes gives the clinician a foundation upon which to base treatment decisions. Assigning products to generic dressing categories further facilitates dressing selection, allowing the treatment protocol to be individualized to the patient, the wound, and the setting.