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61.
The Saliency Network proposed by Shashua and Ullman (1988) is a well-known approach to the problem of extracting salient curves from images while performing gap completion. This paper analyzes the Saliency Network. The Saliency Network is attractive for several reasons. First, the network generally prefers long and smooth curves over short or wiggly ones. While computing saliencies, the network also fills in gaps with smooth completions and tolerates noise. Finally, the network is locally connected, and its size is proportional to the size of the image.Nevertheless, our analysis reveals certain weaknesses with the method. In particular, we show cases in which the most salient element does not lie on the perceptually most salient curve. Furthermore, in some cases the saliency measure changes its preferences when curves are scaled uniformly. Also, we show that for certain fragmented curves the measure prefers large gaps over a few small gaps of the same total size. In addition, we analyze the time complexity required by the method. We show that the number of steps required for convergence in serial implementations is quadratic in the size of the network, and in parallel implementations is linear in the size of the network. We discuss problems due to coarse sampling of the range of possible orientations. Finally, we consider the possibility of using the Saliency Network for grouping. We show that the Saliency Network recovers the most salient curve efficiently, but it has problems with identifying any salient curve other than the most salient one. 相似文献
62.
This survey focuses on the mechanical properties of spruce tonal wood from three different locations in the canton of Grisons, Switzerland. In addition, the material from one location was stored under water for three months in order to test the influence of extractives. The tests included the analysis of the annual ring structure, measurements of the sound velocity with longitudinal and transverse waves in the three main directions, bending strength, bending modulus of elasticity (MOE), eigenfrequency, logarithmic decrement of the damping, sorption and swelling. Single specimens were taken to measure the extractives content. The tested wood properties suggest tonal wood of high quality for all the locations. No significant differences of the wood properties, except density-related ones, were found between the three locations. The water storage resulted in the removal of extractives, but no significant change in properties could be found. 相似文献
63.
This study examined whether the positive or negative valence of a news story, and the race of the character portrayed in the story, would influence Black or White readers' selection of a story. The study employed selective exposure methodology to unobtrusively measure story selections among Black and White readers as they browsed a news site. The results demonstrated Black newsreaders were more likely to select and read positive and negative stories featuring their racial ingroup, and more likely to select and read negative vis‐à‐vis positive stories about their outgroup. In contrast, Whites' story preference was not affected by story valence or character race. Theoretical assumptions from social identity, social comparison, and social cognitive theories are used to explain the findings. 相似文献
64.
65.
An aggregation of 14 cases of amyotrophic lateral sclerosis (ALS) was encountered in two families in Minnesota. Although the classical clinical features of ALS predominated, some members of one family showed, in addition, extrapyramidal signs, peripheral sensory impairment in the upper and lower limbs and mild mental fallout. Autosomal dominant inheritance with incomplete penetrance was the most likely mode of transmission. Pathological changes were the same as those seen in sporadic ALS although one patient also showed degeneration of the substantia nigra. These two families were compared to others in the literature and an effort was made to refine the classification of familial ALS. 相似文献
66.
A patient is described who developed a delayed hemolytic transfusion reaction, 11 days posttransfusion, caused by anti-U. This case illustrates the difficulty that can occur in distinguishing a delayed transfusion reaction from autoimmune hemolytic disease when the antibody involved is directed against a high incidence blood group antigen. 相似文献
67.
Screening of common adhesives showed that polyurethanes, as a class, to be most suitable for adhering to wet tooth tissue. The isocyanate groups in the adhesive may react with the tooth mineral; this view is supported by a number of approaches, including measuring γc at several humidities, which may be interpreted as showing tooth tissue surfaces to be rich in hydroxyl groups. The bonding of polyurethanes to enamel could be improved by pre-treatments (including acid etching and acetone drying) and by proper choice of polyol, fillers, and coupling agents. From scanning electron micrographs the etching is interpreted to debride a weak boundary layer. The preferred formulation was a TiO2-filled polyurethane formed from equal weights of castor oil and polymethylene polyphenyl isocyanate catalyzed by from 1 ½ to 10% of tin octoate. Joints of teeth bonded with polyurethanes withstood long-term exposures to water and synthetic saliva and dental restorations in rabbits appeared to adapt well. 相似文献
68.
The authors examined the effects of exposure to foreign cultural environments and symbols on decision making among European Americans. Although European Americans predicted change less frequently than East Asians did (Pilot Study A), European Americans anticipated greater change when primed with East Asian culturally-laden locations (Pilot Study B and Study 1) and the East Asian yin–yang symbol (Studies 2–7). These effects held in the domains of stock prediction and weather forecasting and were stronger the more familiar European Americans were with the cultural primes, and the longer they had spent overseas. Together, these findings suggest that familiar culturally-laden cues sometimes prime people within one cultural milieu to make so-called extracultural judgments. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
69.
A case in which a growing and painful mass developed in the breast 10 months after fat injection following trochanteric and abdominal liposuction is described. Treatment included lumpectomy and breast reconstruction in a second stage by bilateral subpectoral augmentation mammaplasty with textured gel-filled prostheses. Histologic examination revealed a liponecrotic pseudocyst. The development of pseudocysts and microcalcifications after breast autologous fat injection is a complication that warns against using this technique for breast augmentation. 相似文献
70.
A Marrone JW Shih Y Nakatsuji HJ Alter D Lau J Vergalla JH Hoofnagle 《Canadian Metallurgical Quarterly》1997,92(11):1992-1996
OBJECTIVES: The hepatitis G virus (HGV) is a newly described flavivirus that affects a high proportion of patients with chronic viral hepatitis: our objective was to determine what role HGV might play in the course of disease. METHODS: We evaluated stored serum samples from 108 patients with chronic hepatitis B and 99 patients with chronic hepatitis C who participated in trials of alpha-interferon or ribavirin for the presence of hepatitis B virus (HBV) DNA and hepatitis C virus (HCV) RNA by branched DNA and for the presence of HGV RNA by polymerase chain reaction (PCR), using primers from the NS5 region of the genome. RESULTS: Initially, 20 (19%) patients with hepatitis B and 11 (11%) with hepatitis C had HGV RNA in their serum. Patients with and without HGV infection were similar with regard to clinical features, laboratory tests, and hepatic histology. HGV RNA levels fell during interferon therapy and became undetectable in those receiving the highest doses; however, HGV RNA levels returned to pretreatment values when therapy was stopped. With ribavirin therapy, HGV RNA levels did not change. Two- to 12-yr follow-up serum samples were available from 17 initially HGV RNA-positive patients, of whom only 10 (59%) were still positive. CONCLUSIONS: HGV infection is common among patients with chronic hepatitis B and C but has little effect on the short-term course of disease or response to therapy. HGV RNA levels are suppressed but not eradicated by alpha-interferon and are unaffected by ribavirin treatment. Spontaneous loss of HGV RNA occurs over time in a proportion of patients. 相似文献