2,382 research outputs found
Direct Methods in High Resolution Electron Microscopy
New approaches are proposed to retrieve the wavefunction at the object and from this, to retrieve the projected structure of the object. The wavefunction is retrieved by capturing images at a series of closely spaced focus values and to process the whole 3D data. The structure of the object is retrieved using a formalism based on electron channelling
Organizational error management culture and its impact on performance: a two study replication
The authors argue that a high-organizational error management culture, conceptualized to include norms and common practices in organizations (e.g., communicating about errors, detecting, analyzing, and correcting errors quickly), is pivotal to the reduction of negative and the promotion of positive error consequences. Organizational error management culture was positively related to firm performance across 2 studies conducted in 2 different European countries. On the basis of quantitative and qualitative cross-sectional data from 65 Dutch organizations, Study 1 revealed that organizational error management culture was significantly correlated with both organizational goal achievement and an objective indicator of economic performance. This finding was confirmed in Study 2, using change-of-profitability data from 47 German organizations. The results suggest that organizations may want to introduce organizational error management as a way to boost firm performance
Shear banding in torsion shear tests on cross-anisotropic deposits of fine Nevada sand
AbstractA series of torsion shear experiments was performed on large hollow cylinder specimens of Fine Nevada sand with major principal stress directions relative to vertical, α, varying from 0° to 90° and with the intermediate principal stress, Ï2, varying from Ï3 to Ï1 as indicated by b=(Ï2âÏ3)/(Ï1âÏ3). The Fine Nevada sand was deposited by dry pluviation, thus producing a sand fabric with horizontal bedding planes and cross-anisotropic characteristics. The various stress conditions were achieved by varying the pressures inside and outside the hollow cylinder specimen relative to the shear stress and the vertical deviator stress according to a pre-calculated pattern. All stresses and all strains were determined from careful measurements so that analysis of the soil behavior could be made reliably. The soil behavior was determined for a pattern of combinations of α varying with increments of 22.5° from 0° to 90° and b varying with increments of 0.25 from 0.0 to 1.0. Thus, 25 test locations were established, but many tests were repeated to study the consistency of the results. The friction angles varied considerably with α and b, thus indicating the importance of the intermediate principal stress and the principal stress directions relative to the horizontal bedding planes. The observed shear bands essentially followed the expected directions, but due to the cross-anisotropy shear bands were also observed in the direction of the major principal stress in regions with high b-values. The strength variation was also influenced by the flexibility of the boundaries in these regions
Breaking CPT by mixed non-commutativity
The mixed component of the non-commutative parameter \theta_{\mu M}, where
\mu = 0,1,2,3 and M is an extra dimensional index may violate four-dimensional
CPT invariance. We calculate one and two-loop induced couplings of \theta_{\mu
5} with the four-dimensional axial vector current and with the CPT odd dim=6
operators starting from five-dimensional Yukawa and U(1) theories. The
resulting bounds from clock comparison experiments place a stringent constraint
on \theta_{\mu 5}, |\theta_{\mu 5}|^{-1/2} > 5\times 10^{11} GeV. The orbifold
projection and/or localization of fermions on a 3-brane lead to CPT-conserving
physics, in which case the constraints on \theta{\mu 5} are softened.Comment: 4 pages, latex, 1 figur
Using an audit tool (MAPS Global) to assess the characteristics of the physical environment related to walking for transport in youth : reliability of Belgian data
Background: The aim was to examine inter-rater and alternate-form reliability of the Microscale Audit of Pedestrian Streetscapes (MAPS) Global tool to assess the physical environment along likely walking routes in Belgium.
Methods: For 65 children participating in the BEPAS-children study, routes between their individual homes and the nearest pre-defined destination were defined. Using MAPS Global, physical environmental characteristics of the routes were audited by 4 trained auditors (2 on-site, 2 online using Google Street View). Inter-rater reliability was studied for on-site and online ratings separately. Alternate-form reliability was examined by comparing on-site with online ratings.
Results: Inter-rater reliability for on-site ratings was acceptable for 68% of items (kappa range 0.03â1.00) and for online ratings for 60% of items (kappa range â0.03 to 1.00). Acceptable alternate-form reliability was reported for 60% of items (kappa range â0.01 to 1.00/r range 0.31â1.00).
Conclusions: MAPS Global can be used to assess the physical environment of potential walking routes. For areas where Google Street View imagery is widely covered and often updated, MAPS Global can be completed online
Predictive performance of front-loaded experimentation strategies in pharmaceutical discovery : a Bayesian perspective
Experimentation is a significant innovation process activity and its design is fundamental to the learning and knowledge build-up process. Front-loaded experimentation is known as a strategy seeking to improve innovation process performance; by exploiting early information to spot and solve problems as upstream as possible, costly overruns in subsequent product development are avoided. Although the value of search through front-loaded experimentation in complex and novel environments is recognized, the phenomenon has not been studied in the highly relevant pharmaceutical R&D context, where typically lots of drug candidates get killed very late in the innovation process when potential problems are insufficiently anticipated upfront. In pharmaceutical research the initial problem is to discover a âdrug-likeâ complex biological or chemical system that has the potential to affect a biological target on a disease pathway. My case study evidence found that the discovery process is managed through a front-loaded experimentation strategy. The research team gradually builds a mental model of the drugâs action in which the solution of critical design problems can be initiated at various moments in the innovation process. The purpose of this research was to evaluate the predictive performance of frontloaded experimentation strategies in the discovery process. Because predictive performance necessitates conditional probability thinking, a Bayesian methodology is proposed and a rationale is given to develop research propositions using Monte Carlo simulation. An adaptive system paradigm, then, is the basis for designing the simulation model used for top-down theory development. My simulation results indicate that front-loaded strategies in a pharmaceutical discovery context outperform other strategies on positive predictive performance. Frontloaded strategies therefore increase the odds for compounds succeeding subsequent development testing, provided they were found positive in discovery. Also, increasing the number of parallel concept explorations in discovery influences significantly the negative predictive performance of experimentation strategies, reducing the probability of missed opportunities in development. These results are shown to be robust for varying degrees of predictability of the discovery process. The counterintuitive business implication of my research findings is that the key to further reduce spend and overruns in pharmaceutical development is to be found in discovery, where efforts to better understand drug candidates lead to higher success rates later in the innovation process.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
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