5,405 research outputs found
[NASA/DOD Aerospace Knowledge Diffusion Research Project. Paper 2:] External Information Sources and aerospace R&D: The use and importance of technical reports by US aerospace engineers and scientists
This paper formulates and studies two propositions. Proposition 1 states that information that is external to the aerospace organization tends to be used less than internal sources of information; the more geographically removed the information is from the organization, the less likely it is to be used. Proposition 2 states that of the various sociometric variables assumed to influence the use of an information channel or source, perceived accessibility exerts the greatest influence. Preliminary analysis based on surveys supports Proposition 1. This analysis does not support Proposition 2, however. Evidence here indicates that reliability and relevance influence the use of an information source more than the idea of perceived accessibility
FDDI network test adaptor error injection circuit
An apparatus for injecting errors into a FDDI token ring network is disclosed. The error injection scheme operates by fooling a FORMAC into thinking it sent a real frame of data. This is done by using two RAM buffers. The RAM buffer normally accessed by the RBC/DPC becomes a SHADOW RAM during error injection operation. A dummy frame is loaded into the shadow RAM in order to fool the FORMAC. This data is just like the data that would be used if sending a normal frame, with the restriction that it must be shorter than the error injection data. The other buffer, the error injection RAM, contains the error injection frame. The error injection data is sent out to the media by switching a multiplexor. When the FORMAC is done transmitting the data, the multiplexor is switched back to the normal mode. Thus, the FORMAC is unaware of what happened and the token ring remains operational
The Swing Voter’s Curse in the Laboratory
This paper reports the first laboratory study of the swing voter’s curse and provides insights on the larger theoretical and empirical literature on "pivotal voter" models. Our experiment controls for different information levels of voters, as well as the size of the electorate, the distribution of preferences, and other theoretically relevant parameters. The design varies the share of partisan voters and the prior belief about a payoff relevant state of the world. Our results support the equilibrium predictions of the Feddersen-Pesendorfer model, and clearly reject the notion that voters in the laboratory use naive decision-theoretic strategies. The voters act as if they are aware of the swing voter’s curse and adjust their behavior to compensate. While the compensation is not complete and there is some heterogeneity in individual behavior, we find that aggregate outcomes, such as efficiency, turnout, and margin of victory, closely track the theoretical predictions
Synthesis of star-branched poly(vinyl alcohol) and ice recrystallization inhibition activity
Antifreeze proteins are potent inhibitors of ice crystal growth (recrystallization), which is a highly desirable property for cryopreservation and other low temperature applications. It has
emerged that relatively simple polymers based on poly(vinyl alcohol) can mimic this activity, but the link between architecture and activity is not known. Here, a trifunctional xanthate was designed and synthesized to prepare star-branched poly(vinyl alcohols) by RAFT/Xanthate mediated polymerization, and their ice growth inhibition activity probed for the first time. The trifunctional agent design affords the formation of well-defined star polymers, with no evidence
of star-star linking, even at high conversions, and narrow molecular weight dispersity. It is observed that three-arm stars have identical activity to two-armed (i.e. linear) equivalents, suggesting that the total hydrodynamic size of the polymer (diameter three-arm ~ two-arm)
rather than total valence of the functional groups is the key descriptor of activit
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Enhanced macrophage tropism of HIV in brain and lymphoid tissues is associated with sensitivity to the broadly neutralizing CD4 binding site antibody b12
Macrophages in the central nervous system (CNS) and other tissues are an important cellular reservoir for human immunodeficiency virus type 1 (HIV) infection, particularly in the later stages of disease. Macrophage-tropic HIV strains have an enhanced capacity to enter cells expressing low levels of CD4 through mechanisms that are not well understood. Here, we use a panel of primary HIV envelopes from brain and lymphoid tissues to examine the relationship between neutralization sensitivity to reagents targeting the CD4 binding site and virus entry into macrophages. Neutralization assays using pseudotyped viruses showed an association between the capacity of HIV to enter macrophages and increased sensitivity to the broadly neutralizing monoclonal antibody (mAb) b12, which recognizes a conserved epitope overlapping the CD4 binding site, but not sensitivity to soluble CD4 (sCD4) or b6, a non-neutralizing CD4 binding site mAb. Furthermore, loss of an N-linked glycosylation site at position 386 in the V4 region of Env enhanced macrophage tropism together with b12 sensitivity, but not neutralization by sCD4, b6, or a broadly neutralizing AIDS patient serum. These findings suggest that exposure of the b12 epitope, rather than exposure of the CD4 binding site per se, enhances HIV macrophage tropism, possibly by exposing a region on the outer domain of gp120 that is initially recognized by CD4. These findings suggest overlap between specific gp120 determinants in or near the b12 epitope and those conferring macrophage tropism
Enhancing the Power Output of Bifacial Solar Modules by Applying Effectively Transparent Contacts (ETCs) With Light Trapping
We have performed a computational study on the enhancement of the power output of bifacial solar modules with effectively transparent contacts (ETCs). ETCs are triangular cross-sectional silver grid fingers that redirect light to the active area of the solar cell, therefore mitigating grid finger shading losses. Furthermore, ETCs can be spaced densely leading to light trapping. We modeled bifacial silicon heterojunction solar modules with varying front and rear illumination and ETC coverages. We determined that shading losses can be almost fully mitigated and that light absorption can be increased by up to 4.7% compared with state-of-the-art screen-printed bifacial modules. Furthermore, we calculated that grid resistance and silver usage can be improved when using ETCs
Quality of Statistical Match and Employment Simulations Used in the Estimation of the Levy Institute Measure of Time and Income Poverty (LIMTIP) for South Korea, 2009
The quality of match of the statistical match used in the LIMTIP estimates for South Korea in 2009 is described. The match combines the 2009 Korean Time Use Survey (KTUS 2009) with the 2009 Korean Welfare Panel Study (KWPS 2009). The alignment of the two datasets is examined, after which various aspects of the match quality are described. The match is of high quality, given the nature of the source datasets. The method used to simulate employment response to availability of jobs in the situation in which child-care subsidies are available is described. Comparisons of the donor and recipient groups for each of three stages of hot-deck statistical matching are presented. The resulting distribution of jobs, earnings, usual hours of paid employment, household production hours, and use of child-care services are compared to the distribution in the donor pools. The results do not appear to be anomalous, which is the best that can be said of the results of such a procedure
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