An experimental program for the investigation of panel instabilities caused by shock waves

Experimental methods and apparatus for studying panel instabilities caused by shock wave

Experimental study of shock-panel coupling - Preliminary results

Shock-panel coupling effects of supersonic turbulent flow driven by impedance hea

Automated parameters for troubled-cell indicators using outlier detection

In Vuik and Ryan (2014) we studied the use of troubled-cell indicators for discontinuity detection in nonlinear hyperbolic partial differential equations and introduced a new multiwavelet technique to detect troubled cells. We found that these methods perform well as long as a suitable, problem-dependent parameter is chosen. This parameter is used in a threshold which decides whether or not to detect an element as a troubled cell. Until now, these parameters could not be chosen automatically. The choice of the parameter has impact on the approximation: it determines the strictness of the troubled-cell indicator. An inappropriate choice of the parameter will result in detection (and limiting) of too few or too many elements. The optimal parameter is chosen such that the minimal number of troubled cells is detected and the resulting approximation is free of spurious oscillations. In this paper we will see that for each troubled-cell indicator the sudden increase or decrease of the indicator value with respect to the neighboring values is important for detection. Indication basically reduces to detecting the outliers of a vector (one dimension) or matrix (two dimensions). This is done using Tukey's boxplot approach to detect which coefficients in a vector are straying far beyond others (Tukey, 1977). We provide an algorithm that can be applied to various troubled-cell indication variables. Using this technique the problem-dependent parameter that the original indicator requires is no longer necessary as the parameter will be chosen automatically

Entry and Patenting in the Software Industry

To what extent are firms kept out of a market by patents covering related technologies? Do patents held by potential entrants make it easier to enter markets? We estimate the empirical relationship between market entry and patents for 27 narrowly defined categories of software products during the period 1990-2004. Controlling for demand, market structure, average patent quality, and other factors, we find that a 10% increase in the number of patents relevant to market reduces the rate of entry by 3-8%, and this relationship intensified following expansions in the patentability of software in the mid-1990s. However, potential entrants with patent applications relevant to a market are more likely to enter it. Finally, patents appear to substitute for complementary assets in the entry process, as patents have both greater entry-deterring and entry-promoting effects for firms without prior experience in other markets.

Four Scottish indulgences at Sens

English interest in the great Cistercian abbey of Pontigny was stimulated by the exiles there of two archbishops of Canterbury, Thomas Becket and Stephen Langton.1 As archbishops of Canterbury, Langton and Edmund of Abingdon made gifts to Pontigny abbey in consideration of the welcome given to Becket.2 Edmund did not die at Pontigny, but was a confrater of the community, and the abbot claimed the body, asserting that Edmund had expressed a wish to be buried there. The process of canonisation was rapid.3 After Edmund's canonisation, Henry III sent a chasuble and a chalice for the first celebration of the feast, and granted money to maintain four candles round the saint's shrine.4 In 1254, en route from Gascony to meet Louis IX in Chartres and Paris,5 Henry visited Pontigny, as his brother Richard of Cornwall, who seems to have pressed for canonisation, had done in 1247.6 Archbishop Boniface of Canterbury ordered the celebration of the feast to be observed throughout his province.7 Pope Alexander IV granted a dispensation to allow Englishwomen to enter the precinct of Pontigny abbey on the feast of the translation of the relics of St Edmund8 (women were normally forbidden to enter a Cistercian monastery). Matthew Paris, the greatest English chronicler of the age, wrote a life of the saint.9 English interest continued into the fourteenth century. In 1331 an English priest was given a licence to visit the shrine,10 but it seems likely that the Hundred Years’ War made pilgrimage to Pontigny difficult.11 The indulgences preserved by the abbey reveal an interest in the shrine throughout the Western Church, granted as they were by prelates from Tortosa to Livonia and Estonia, and from Messina to Lübeck.1

Historical roots of Agile methods: where did “Agile thinking” come from?

The appearance of Agile methods has been the most noticeable change to software process thinking in the last fifteen years [16], but in fact many of the “Agile ideas” have been around since 70’s or even before. Many studies and reviews have been conducted about Agile methods which ascribe their emergence as a reaction against traditional methods. In this paper, we argue that although Agile methods are new as a whole, they have strong roots in the history of software engineering. In addition to the iterative and incremental approaches that have been in use since 1957 [21], people who criticised the traditional methods suggested alternative approaches which were actually Agile ideas such as the response to change, customer involvement, and working software over documentation. The authors of this paper believe that education about the history of Agile thinking will help to develop better understanding as well as promoting the use of Agile methods. We therefore present and discuss the reasons behind the development and introduction of Agile methods, as a reaction to traditional methods, as a result of people's experience, and in particular focusing on reusing ideas from histor

Patent thickets, licensing and innovative performance

We examine the relationship between fragmented intellectual property (IP) rights and the innovative performance of firms, taking into consideration the role played by in-licensing of IP. We find that firms facing more fragmented IP landscapes have a higher probability of in-licensing. For firms with small patent portfolios we also find a positive association between fragmentation and licensing costs as a share of sales. We observe a negative relationship between IP fragmentation and innovative performance, but only for firms that engage in in-licensing. In contrast, greater IP fragmentation is associated with higher innovative performance for firms that do not in-license. Furthermore, the effects of fragmentation on innovation also appear to depend on the size of a firm’s patent portfolio. These results suggest that the effects of fragmentation of upstream IP rights are not uniform, and instead vary according to the characteristics of the downstream firm. --patent thickets,licensing,innovative performance

Fax Magic; Technology Alert, September 1993

https://egrove.olemiss.edu/aicpa_news/2847/thumbnail.jp

Acoustic fatigue and sound transmission characteristics of a ram composite panel design

An experimental study to determine the acoustic fatigue characteristics of a flat multi-layered structural panel is described. The test panel represented a proposed design for the outer skin of a research application module to be housed within the space shuttle orbiter vehicle. The test specimen was mounted in one wall of the Wyle 100,000 cu ft reverberation room and exposed to a broadband acoustic environment having an overall level of 145 db. The test panel was exposed to nine separate applications of the acoustic environment, each application consisting of 250 seconds duration. Upon completion of the ninth test run, the specimen was exposed to a simulated micrometeoroid impact near the panel center. One additional test run of 250 seconds duration was then performed to complete the overall simulation of 50 flight missions. The experimental results show that no significant fatigue damage occurred until the test specimen was exposed to a simulated micrometeoroid impact. The intermediate foam layer forming the core of the test specimen suffered considerable damage due to this impact, causing a marked variation in the dynamic characteristics of the overall test panel. During the final application of the acoustic environment, the strain and acceleration response spectra showed considerable variation from those spectra obtained prior to impact of the panel. Fatigue damage from acoustic loading however, was limited to partial de-bonding around the edges of the composite panel