11,726 research outputs found
A semantic-based system for querying personal digital libraries
This is the author's accepted manuscript. The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-540-28640-0_4. Copyright @ Springer 2004.The decreasing cost and the increasing availability of new technologies is enabling people to create their own digital libraries. One of the main topic in personal digital libraries is allowing people to select interesting information among all the different digital formats available today (pdf, html, tiff, etc.). Moreover the increasing availability of these on-line libraries, as well as the advent of the so called Semantic Web [1], is raising the demand for converting paper documents into digital, possibly semantically annotated, documents. These motivations drove us to design a new system which could enable the user to interact and query documents independently from the digital formats in which they are represented. In order to achieve this independence from the format we consider all the digital documents contained in a digital library as images. Our system tries to automatically detect the layout of the digital documents and recognize the geometric regions of interest. All the extracted information is then encoded with respect to a reference ontology, so that the user can query his digital library by typing free text or browsing the ontology
On the feasibility of iron or chromium substitution for aluminium in the Al13-Keggin ion
Al-27 NMR measurements in the liquid and the solid state supplemented with chemical analysis of the mixed salts; unambiguously reveal that neither tetrahedral nor octahedral aluminium can be substituted by either iron or chromium in Al-13-Keggin ion salts prepared by conventional methods
Motivations and locational factors of FDI in CIS countries: Empirical evidence from South Korean FDI in Kazakhstan, Russia, and Uzbekistan
Considering the growing significance of Eurasian economic ties because of
South Korea s New Northern Policy and Russia s New Eastern Policy, this study
investigates the motivations and locational factors of South Korean foreign
direct investment (FDI) in three countries in the Commonwealth of Independent
States (CIS: Kazakhstan, Russia, and Uzbekistan) by employing panel analysis
(pooled ordinary least squares (OLS), fixed effects, random effects) using data
from 1993 to 2017. The results show the positive and significant coefficients
of GDP, resource endowments, and inflation. Unlike conventional South Korean
outward FDI, labour-seeking is not defined as a primary purpose. Exchange
rates, political rights, and civil liberties are identified as insignificant.
The authors conclude that South Korean FDI in Kazakhstan, Russia, and
Uzbekistan is associated with market-seeking (particularly in Kazakhstan and
Russia) and natural resource-seeking, especially the former. From a policy
perspective, our empirical evidence suggests that these countries host
governments could implement mechanisms to facilitate the movement of goods
across regions and countries to increase the attractiveness of small local
markets. The South Korean government could develop financial support and risk
sharing programmes to enhance natural resource-seeking investments and mutual
exchange programmes to overcome the red syndrome complex in South Korean
society
Detailed survey of the phase space around Nix and Hydra
We present a detailed survey of the dynamical structure of the phase space
around the new moons of the Pluto - Charon system. The spatial elliptic
restricted three-body problem was used as model and stability maps were created
by chaos indicators. The orbital elements of the moons are in the stable domain
both on the semimajor axis - eccentricity and - inclination spaces. The
structures related to the 4:1 and 6:1 mean motion resonances are clearly
visible on the maps. They do not contain the positions of the moons, confirming
previous studies. We showed the possibility that Nix might be in the 4:1
resonance if its argument of pericenter or longitude of node falls in a certain
range. The results strongly suggest that Hydra is not in the 6:1 resonance for
arbitrary values of the argument of pericenter or longitude of node.Comment: Published in MNRAS. 10 pages, 7 figures, 4 table
Analysis of the Precision of Variable Flip Angle T1 Mapping with Emphasis on the Noise Propagated from RF Transmit Field Maps
In magnetic resonance imaging, precise measurements of longitudinal relaxation time (T1) is crucial to acquire useful information that is applicable to numerous clinical and neuroscience applications. In this work, we investigated the precision of T1 relaxation time as measured using the variable flip angle method with emphasis on the noise propagated from radiofrequency transmit field (B1+) measurements. The analytical solution for T1 precision was derived by standard error propagation methods incorporating the noise from the three input sources: two spoiled gradient echo (SPGR) images and a B1+ map. Repeated in vivo experiments were performed to estimate the total variance in T1 maps and we compared these experimentally obtained values with the theoretical predictions to validate the established theoretical framework. Both the analytical and experimental results showed that variance in the B1+ map propagated comparable noise levels into the T1 maps as either of the two SPGR images. Improving precision of the B1+ measurements significantly reduced the variance in the estimated T1 map. The variance estimated from the repeatedly measured in vivoT1 maps agreed well with the theoretically-calculated variance in T1 estimates, thus validating the analytical framework for realistic in vivo experiments. We concluded that for T1 mapping experiments, the error propagated from the B1+ map must be considered. Optimizing the SPGR signals while neglecting to improve the precision of the B1+ map may result in grossly overestimating the precision of the estimated T1 values
Capsular polysaccharide production and serum survival of Vibrio vulnificus are dependent on antitermination control by RfaH
© 2016 Federation of European Biochemical Societies The human pathogen Vibrio vulnificus undergoes phase variation among colonial morphotypes, including a virulent opaque form which produces capsular polysaccharide (CPS) and a translucent phenotype that produces little or no CPS and is attenuated. Here, we found that a V. vulnificus mutant defective for RfaH antitermination control showed a diminished capacity to undergo phase variation and displayed significantly reduced distal gene expression within the Group I CPS operon. Moreover, the rfaH mutant produced negligible CPS and was highly sensitive to killing by normal human serum, results which indicate that RfaH is likely essential for virulence in this bacterium
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