No local cancellation between directionally opposed first-order and second-order motion signals

AbstractDespite strong converging evidence that there are separate mechanisms for the processing of first-order and second-order motion, the issue remains controversial. Qian, Andersen and Adelson (J. Neurosci., 14 (1994), 7357–7366) have shown that first-order motion signals cancel if locally balanced. Here we show that this is also the case for second-order motion signals, but not for a mixture of first-order and second-order motion even when the visibility of the two types of stimulus is equated. Our motion sequence consisted of a dynamic binary noise carrier divided into horizontal strips of equal height, each of which was spatially modulated in either contrast or luminance by a 1.0 c/deg sinusoid. The modulation moved leftward or rightward (3.75 Hz) in alternate strips. The single-interval task was to identify the direction of motion of the central strip. Three conditions were tested: all second-order strips, all first-order strips, and spatially alternated first-order and second-order strips. In the first condition, a threshold strip height for the second-order strips was obtained at a contrast modulation depth of 100%. In the second condition, this height was used for the first-order strips, and a threshold was obtained in terms of luminance contrast. These two previously-obtained threshold values were used to equate visibility of the first-order and second-order components in the third condition. Direction identification, instead of being at threshold, was near-perfect for all observers. We argue that the first two conditions demonstrate local cancellation of motion signals, whereas in the third condition this does not occur. We attribute this non-cancellation to separate processing of first-order and second-order motion inputs

Are All Patent Examiners Equal? The Impact of Examiner Characteristics

Building on insights gained from interviewing administrators and patent examiners at the United States Patent and Trademark Office (USPTO), we collect and analyze a novel dataset on patent examiners and patent outcomes. This dataset is based on 182 patents for which the Court of Appeals for the Federal Circuit (CAFC) ruled on validity between 1997 and 2000. For each patent, we identify a USPTO primary examiner, and collect historical statistics derived from their entire patent examination history. These data are used to explore a number of hypotheses about the connection between the patent examination process and the strength of ensuing patent rights. Our main findings are as follows. (i) Patent examiners and the patent examination process are not homogeneous. There is substantial variation in observable characteristics of patent examiners, such as their tenure at the USPTO, the number of patents they have examined and the degree to which the patents that they examine are later cited by other patents. (ii) There is no evidence that examiner experience or workload at the time a patent is issued affects the probability that the CAFC finds a patent invalid. (iii) Examiners whose patents tend to be more frequently cited tend to have a higher probability of a CAFC invalidity ruling. The results suggest that all patent examiners are not equal, and that one of the roles of the CAFC is to review the exercise of discretion in the patent examination process.

Position and Energy Controlled Impact Treatment for Increasing Strength and Ductility in Stainless Steel

Graduate Applie

Archaeological Data and Small Projects: A Case Study from the Pyla-Koustopetria Archaeological Project on Cyprus

A case study in how small projects use digital tools

Crime and Greenspace: Extending the Analysis Across Cities

The role of greenspace in urban areas has become a focus of research as municipalities seek to increase the quality of life in cities. Multiple benefits are found to be associated with greenspace, but disservices such as crime are often overlooked. Studies investigating the link between crime and greenspace have revealed mixed results and been limited in geographic scope. This dissertation sought to examine the crime and greenspace relationship, extending the analysis to multiple cities in order to describe how the relationship may vary in different contexts. Additionally, one possible cause of crime, increased temperatures, was investigated to determine how greenspace may moderate the impact of hot weather on crime risk. As urban parks are an important type of greenspace, the relationship between proximity to parks and crime was examined in four case cities. Parks are typically green areas of cities but also encompass less green land uses. This broad analysis revealed a more comprehensive understanding of how crime and greenspace are related which can inform residents and decision-makers of the benefits and possible drawbacks from including greenspace in city and community development