Vacuum deposition apparatus Patent

Describing apparatus used in vacuum deposition of thin film inductive windings for spacecraft microcircuitr

Evaporant source for vapor deposition Patent

Spatter proof evaporant source design for use in vacuum deposition of solid thin films on substrate

Learning, Internal Research, and Spillovers Evidence from a Sample of R&D Laboratories

This paper presents new evidence on the practice of industrial Research and Development (R&D), especially the allocation between learning and internal research, and the role of outside knowledge, as represented by R&D spillovers, in reshaping this allocation. The evidence describes the sources of outside knowledge, portrays the flow of that knowledge into firms, and interprets the channels by which outside knowledge influences R&D. The empirical work is based on a sample of 220 R&D laboratories owned by 115 firms in the U.S. chemicals, machinery, electrical equipment, and motor vehicles industries. The findings are consistent with the view that universities and firms generate technological opportunities in R&D laboratories. In addition to partnerships that define rather strict channels of opportunity, the paper uncovers broader effects of R&D spillovers. The results also suggest that academic spillovers drive learning about universities, and that industrial spillovers drive learning about industry. In this way externally derived opportunities reshape the rate and direction of R&D. Overall the findings paint an image of practitioners of industrial R&D reaching aggressively for opportunities, rather than waiting for opportunities to come to them.

Endogenous R&D Spillovers and Industrial Research Productivity

This paper explores the implications of a simple model of learning and innovation by firms. In this model R&D spillovers are partly determined by firms, rather than by the given economic environment. According to this approach the full effect of spillovers on research productivity of firms exceeds the structural effect because it includes an active learning' response of firms to new information. Furthermore, effective spillovers grow faster or slower than potential spillovers, depending on the returns to scale of production processes for learning and invention. The empirical work is based on a sample of R&D laboratories in the chemicals, machinery, electrical equipment, and transportation equipment industries. I estimate negative binomial regressions for the number of patents as a function of academic and industrial spillover pools, learning expenditures and internal research expenditures. The findings are consistent with the view that learning expenditures transmit the effect of spillovers. I also perform tobit, ordered probit and grouped probit estimation of learning effort. I find that learning effort increases in response to industrial and academic R&D spillovers. Lastly, academic spillovers appear to have a more pervasive effect on R&D than do industrial spillovers. Overall these results suggest a sequence of events underlying learning and innovation, with learning responding to opportunities, innovation responding to learning and own R&D, and a stream of innovations leading to the accumulation of new product introductions that ultimately are reflected in the value of enterprise.

The energy dependence of p_t angular correlations inferred from mean-p_t fluctuation scale dependence in heavy ion collisions at the SPS and RHIC

We present the first study of the energy dependence of pt angular correlations inferred from event-wisemean transverse momentum (pt) fluctuations in heavy ion collisions. We compare our large-acceptancemeasurements at CM energies √^sNN = 19.6, 62.4, 130 and 200 GeV to SPS measurements at 12.3 and 17.3 GeV. p_t angular correlation structure suggests that the principal source of p_t correlations and fluctuations is minijets (minimum-bias parton fragments). We observe a dramatic increase in correlations and fluctuations from SPS to RHIC energies, increasing linearly with ln √^sNN from the onset of observable jet-related (p_t) fluctuations near 10 GeV

Energy absorption mechanisms during crack propagation in metal matrix composites

The stress distributions around individual fibers in a unidirectional boron/aluminum composite material subjected to axial and transverse loadings are being studied utilizing a generalized plane strain finite element analysis. This micromechanics analysis was modified to permit the analysis of longitudinal sections, and also to incorporate crack initiation and propagation. The analysis fully models the elastoplastic response of the aluminum matrix, as well as temperature dependent material properties and thermal stress effects. The micromechanics analysis modifications are described, and numerical results are given for both longitudinal and transverse models loaded into the inelastic range, to first failure. Included are initially cracked fiber models

Parameters for Twisted Representations

The study of Hermitian forms on a real reductive group $G$ gives rise, in the unequal rank case, to a new class of Kazhdan-Lusztig-Vogan polynomials. These are associated with an outer automorphism $\delta$ of $G$, and are related to representations of the extended group $$. These polynomials were defined geometrically by Lusztig and Vogan in "Quasisplit Hecke Algebras and Symmetric Spaces", Duke Math. J. 163 (2014), 983--1034. In order to use their results to compute the polynomials, one needs to describe explicitly the extension of representations to the extended group. This paper analyzes these extensions, and thereby gives a complete algorithm for computing the polynomials. This algorithm is being implemented in the Atlas of Lie Groups and Representations software

Measurement of the Transverse Single Spin Asymmetry of pp + p↑p^\uparrow →\rightarrow η\eta + XX at s\sqrt{s} = 200 GeV

The measurement of transverse single spin asymmetries ($A_N$) provides insight into the structure of the nucleon. Several mechanisms have been proposed that attempt to explain $A_N$ based on QCD, and additional measurements of $A_N$ for different processes further constrain these models. Using the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC), we study transversely polarized p+p collisions. Results from PHENIX and other experiments show significant asymmetries in the forward region, which could be due to contributions from both the Sivers and the Collins effects. Studying the species as well as the kinematic dependencies of these transverse single spin asymmetries will help to disentangle the origin of the observed asymmetries. Therefore, measurements of $A_N$ with inclusive $\eta$ mesons at forward rapidities are an important tool for the understanding of these asymmetries. In 2008, the PHENIX experiment collected 5.2 pb$^{-1}$ integrated luminosity in $p^\uparrow+p$ collisions at $\sqrt{s}$ = 200 GeV. The status of the asymmetry analysis of $\eta$ mesons at forward rapidity will be shown.Comment: 4 pages, 3 figure

On the Complexity and Performance of Parsing with Derivatives

Current algorithms for context-free parsing inflict a trade-off between ease of understanding, ease of implementation, theoretical complexity, and practical performance. No algorithm achieves all of these properties simultaneously. Might et al. (2011) introduced parsing with derivatives, which handles arbitrary context-free grammars while being both easy to understand and simple to implement. Despite much initial enthusiasm and a multitude of independent implementations, its worst-case complexity has never been proven to be better than exponential. In fact, high-level arguments claiming it is fundamentally exponential have been advanced and even accepted as part of the folklore. Performance ended up being sluggish in practice, and this sluggishness was taken as informal evidence of exponentiality. In this paper, we reexamine the performance of parsing with derivatives. We have discovered that it is not exponential but, in fact, cubic. Moreover, simple (though perhaps not obvious) modifications to the implementation by Might et al. (2011) lead to an implementation that is not only easy to understand but also highly performant in practice.Comment: 13 pages; 12 figures; implementation at http://bitbucket.org/ucombinator/parsing-with-derivatives/ ; published in PLDI '16, Proceedings of the 37th ACM SIGPLAN Conference on Programming Language Design and Implementation, June 13 - 17, 2016, Santa Barbara, CA, US