12,319 research outputs found
Globalization and Knowledge Spillover: International Direct Investment, Exports and Patents
This paper examines the impact of the three main channels of international trade on domestic innovation, namely outward direct investment, inward direct investment (IDI) and exports. The number of Triadic patents serves as a proxy for innovation. The data set contains 37 countries that are considered to be highly competitive in the world market, covering the period 1994 to 2005. The empirical results show that increased exports and outward direct investment are able to stimulate an increase in patent output. In contrast, IDI exhibits a negative relationship with domestic patents. The paper shows that the impact of IDI on domestic innovation is characterized by two forces, and the positive effect of cross-border mergers and acquisitions by foreigners is less than the negative effect of the remaining IDI.International direct investment; Export; Triadic Patent; Outward Direct Investment; Inward Direct Investment; R&D; negative binomial model
Parylene stiction
This paper presents a preliminary study into stiction between parylene C and substrate surfaces for biocompatible check-valve applications. During fabrication, parylene C is used as the structural material for the check-valve. The substrate surfaces studied include Au, Al, Si, parylene C, XeF_2 treated Si, and silicon dioxide. Stiction between different surfaces is created after sacrificial photoresist etching. Then, the stiction is measured using blister tests, and stiction mechanisms for different materials are investigated. The devices are released with different recipes to examine their effects. Finally, the results of the study reveal methods to control the cracking pressure of parylene check-valves
Improvement of visual acuity in children with anisometropic amblyopia treated with rotated prisms combined with near activity
<b>AIM:</b> To evaluate the efficacy of a new modality for improving visual acuity (VA) in pediatric patients with anisometropic amblyopia.<b>METHODS:</b> Retrospective and interventional case series. Medical records of 360 children with anisometropic amblyopia treated with a modality that included rotated prisms, lenses, and near activities from January 2008 to January 2012 were analyzed. Characteristics such as improvement of VA and contrast sensitivity in amblyopic eyes and resolution of amblyopia (VA≤0.1logMAR or a difference of ≤2 lines in logMAR between the eyes) were assessed.<b>RESULTS:</b> Among the patients, the mean VA of the amblyopic eyes improved from 0.48logMAR (SD=0.16) to 0.12logMAR (SD=0.16) and the mean VA improvement was 0.36logMAR (SD=0.10, <i>P</i><0.001). Resolution of amblyopia was achieved in 233 of 360 patients (64.72%). The mean time for resolution of amblyopia was 8.05 weeks (SD=4.83) or 14.14 sessions (SD=8.76). Among the study group, refraction error did not change significantly after treatment (<i>P</i>=0.437). We found that better baseline VA may be related to success and shorten the time to amblyopic resolution.<b>CONCLUSION:</b> VA and contrast sensitivity improved with rotated prisms, correcting lenses, and near activities in children with anisometropic amblyopia. The VA improvement by this modality was comparable to other methods. However, the time to resolution of amblyopia was shorter with this method than with other modalities. Rotated prisms combined with near acuity could provide an alternative treatment in children with anisometropic amblyopia who can’t tolerant traditional therapy method like patching
Path deviations outperform approximate stability in heterogeneous congestion games
We consider non-atomic network congestion games with heterogeneous players
where the latencies of the paths are subject to some bounded deviations. This
model encompasses several well-studied extensions of the classical Wardrop
model which incorporate, for example, risk-aversion, altruism or travel time
delays. Our main goal is to analyze the worst-case deterioration in social cost
of a perturbed Nash flow (i.e., for the perturbed latencies) with respect to an
original Nash flow. We show that for homogeneous players perturbed Nash flows
coincide with approximate Nash flows and derive tight bounds on their
inefficiency. In contrast, we show that for heterogeneous populations this
equivalence does not hold. We derive tight bounds on the inefficiency of both
perturbed and approximate Nash flows for arbitrary player sensitivity
distributions. Intuitively, our results suggest that the negative impact of
path deviations (e.g., caused by risk-averse behavior or latency perturbations)
is less severe than approximate stability (e.g., caused by limited
responsiveness or bounded rationality). We also obtain a tight bound on the
inefficiency of perturbed Nash flows for matroid congestion games and
homogeneous populations if the path deviations can be decomposed into edge
deviations. In particular, this provides a tight bound on the Price of
Risk-Aversion for matroid congestion games
Stiction of parylene C to silicon surface measured using blister tests
Micro-fabricated biocompatible check valves are integral parts of many implantable micro-fluidic devices. The cracking pressure of check valves is usually controlled by stiction between polymeric films and the underlying substrate. The following paper presents the first comprehensive study of stiction between parylene and silicon surfaces. The valves are fabricated using surface micromachining with parylene C as the structural material. Deep Reactive Ion Etching (DRIE) is used to create through holes in the wafer for the passage of fluids. Blister test is employed to calculate stiction. From experimental results, stiction between parylene C and silicon surfaces is found to be 2.59 J/m2, which is comparable to the stiction between silicon and other polymeric thin films
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