5,293 research outputs found
Feasibility study of an explosive gun
Feasibility of high performance, explosively driven device, and calculations for deformable piston light gas gu
Concerted reductive coupling of an alkyl chloride at Pt(IV)
Oxidation of a doubly cyclometallated platinum(II) complex results in two isomeric platinum(IV) complexes. Whereas the trans isomer is robust, being manipulable in air at room temperature, the cis isomer decomposes at −20 °C and above. Reductive coupling of an alkyl chloride at the cis isomer gives a new species which can be reoxidised. The independence of this coupling on additional halide rules out the reverse of an SN2 reaction, leaving a concerted process as the only sensible reaction pathway
Keynote Address | Residential Research and Bilateral Knowledge Translation Supporting Community-based Actions
地域環境知プロジェクト第1回国際シンポジウム,総合地球環境学研究所 講演室,2014-09-13,総合地球環境学研究所 地域環境知プロジェク
SlowFuzz: Automated Domain-Independent Detection of Algorithmic Complexity Vulnerabilities
Algorithmic complexity vulnerabilities occur when the worst-case time/space
complexity of an application is significantly higher than the respective
average case for particular user-controlled inputs. When such conditions are
met, an attacker can launch Denial-of-Service attacks against a vulnerable
application by providing inputs that trigger the worst-case behavior. Such
attacks have been known to have serious effects on production systems, take
down entire websites, or lead to bypasses of Web Application Firewalls.
Unfortunately, existing detection mechanisms for algorithmic complexity
vulnerabilities are domain-specific and often require significant manual
effort. In this paper, we design, implement, and evaluate SlowFuzz, a
domain-independent framework for automatically finding algorithmic complexity
vulnerabilities. SlowFuzz automatically finds inputs that trigger worst-case
algorithmic behavior in the tested binary. SlowFuzz uses resource-usage-guided
evolutionary search techniques to automatically find inputs that maximize
computational resource utilization for a given application.Comment: ACM CCS '17, October 30-November 3, 2017, Dallas, TX, US
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Can Institutional Investors Bias Real Estate Portfolio Appraisals? Evidence from the Market Downturn
This paper investigates the extent to which institutional investors may have influenced independent real estate appraisals during the financial crisis. A conceptual model of the determinants of client influence on real estate appraisals is proposed. It is suggested that the extent of clients’ ability and willingness to bias appraisal outputs is contingent upon market and regulatory environments (ethical norms and legal and institutional frameworks), the salience of the appraisal(s) to the client, financial incentives for the appraiser to respond to client pressure, organisational culture, the level of moral reasoning of both individual clients and appraisers, client knowledge and the degree of appraisal uncertainty. The potential of client influence to bias ostensibly independent real estate appraisals is examined using the opportunity afforded by the market downturn commencing in 2007 in the UK. During the market turbulence at the end of 2007, the motivations of different types of owners to bias appraisals diverged clearly and temporarily provided a unique opportunity to assess potential appraisal bias. We use appraisal-based performance data for individual real estate assets to test whether there were significant ownership effects on performance during this period. The results support the hypothesis that real estate appraisals in this period reflected the differing needs of clients.This is the author accepted manuscript. The final version is available from Springer via http://dx.doi.org/10.1007/s10551-015-2953-
Deformation of vortex patches by boundaries
The deformation of two-dimensional vortex patches in the vicinity of fluid
boundaries is investigated. The presence of a boundary causes an initially
circular patch of uniform vorticity to deform. Sufficiently far away from the
boundary, the deformed shape is well approximated by an ellipse. This leading
order elliptical deformation is investigated via the elliptic moment model of
Melander, Zabusky & Styczek [M. V. Melander, N. J. Zabusky & A. S. Styczek, J.
Fluid. Mech., 167, 95 (1986)]. When the boundary is straight, the centre of the
elliptic patch remains at a constant distance from the boundary, and the motion
is integrable. Furthermore, since the straining flow acting on the patch is
constant in time, the problem is that of an elliptic vortex patch in constant
strain, which was analysed by Kida [S. Kida, J. Phys. Soc. Japan, 50, 3517
(1981)]. For more complicated boundary shapes, such as a square corner, the
motion is no longer integrable. Instead, there is an adiabatic invariant for
the motion. This adiabatic invariant arises due to the separation in times
scales between the relatively rapid time scale associated with the rotation of
the patch and the slower time scale associated with the self-advection of the
patch along the boundary. The interaction of a vortex patch with a circular
island is also considered. Without a background flow, conservation of angular
impulse implies that the motion is again integrable. The addition of an
irrotational flow past the island can drive the patch towards the boundary,
leading to the possibility of large deformations and breakup.Comment: 19 pages, 16 figure
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