Brain Structural Networks Associated with Intelligence and Visuomotor Ability

Increasing evidence indicates that multiple structures in the brain are associated with intelligence and cognitive function at the network level. The association between the grey matter (GM) structural network and intelligence and cognition is not well understood. We applied a multivariate approach to identify the pattern of GM and link the structural network to intelligence and cognitive functions. Structural magnetic resonance imaging was acquired from 92 healthy individuals. Source-based morphometry analysis was applied to the imaging data to extract GM structural covariance. We assessed the intelligence, verbal fluency, processing speed, and executive functioning of the participants and further investigated the correlations of the GM structural networks with intelligence and cognitive functions. Six GM structural networks were identified. The cerebello-parietal component and the frontal component were significantly associated with intelligence. The parietal and frontal regions were each distinctively associated with intelligence by maintaining structural networks with the cerebellum and the temporal region, respectively. The cerebellar component was associated with visuomotor ability. Our results support the parieto-frontal integration theory of intelligence by demonstrating how each core region for intelligence works in concert with other regions. In addition, we revealed how the cerebellum is associated with intelligence and cognitive functions

Dynamic characteristics of flow meters for fuel consumption measurement in ships

The dynamic characteristics of various flow meters for fuel consumption measurement aboard shipswere evaluated. The flow rate was measured using the Korea Research Institute of Standards and Science (KRISS) oil flow standard system using K-oil(density : 0.804 g/cm3, viscosity : 3.679 cSt), which has similar fluid properties as diesel oil. The flow meters were tested in a test bed that simulated the vibration conditions in ships. The vibration conditions were established in accordance to vibration standard IEC 60068-2-6 as follows: a±0.7g acceleration and 30 Hz frequency. The K-factors (mL/pulse) of various flow meters (PD meter, turbine flow meter, Coriolis flow meter, and ultrasonic flow meter) were obtained for various flow rates (60 L/h ~ 300 L/h). The PD meter, Coriolis flow meter, and ultrasonic flow meter were found to have almost constant Kfactors according to the flow rates. However, the K-factor of the turbine flow meter was reduced at a low flow rate owing to bearing friction in the turbine blade. The flow rate errors of the PD meter, Coriolis flow meter, and ultrasonic flow meter were found to be under ±0.5 % with and without vibration. However, the flow rate error of the turbine flow meter was approximately -4.3 % at a low flow rate (60 L/h) owing to the friction effect. The Coriolis flow meter had the lowest flow rate error (< 0.1%) according to the flow rate. The vibration influenced the flow rate error of the Coriolis flow meter at high flow rates owing to its measuring principle. However, the difference in flow rate errors was a negligible value (0.05 %) with and without vibration. Therefore, we confirmed that the PD meter, turbine meter, Coriolis flow meter and ultrasonic flow meter could be used for measuring flow rates in ships with a ±0.5 % flow rate error.Papers presented at the 13th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Portoroz, Slovenia on 17-19 July 2017 .International centre for heat and mass transfer.American society of thermal and fluids engineers

Eigenmodes and growth rates of relativistic current filamentation instability in a collisional plasma

I theoretically found eigenmodes and growth rates of relativistic current filamentation instability in collisional regimes, deriving a generalized dispersion relation from self-consistent beam-Maxwell equations. For symmetrically counterstreaming, fully relativistic electron currents, the collisional coupling between electrons and ions creates the unstable modes of growing oscillation and wave, which stand out for long-wavelength perturbations. In the stronger collisional regime, the growing oscillatory mode tends to be dominant for all wavelengths. In the collisionless limit, those modes vanish, while maintaining another purely growing mode that exactly coincides with a standard relativistic Weibel mode. It is also shown that the effects of electron-electron collisions and thermal spread lower the growth rate of the relativistic Weibel instability. The present mechanisms of filamentation dynamics are essential for transport of homogeneous electron beam produced by the interaction of high power laser pulses with plasma.Comment: 44 pages, 12 figures. Accepted for publication in Phys. Rev.

Characterization of thin-film GaAs diodes grown on germanium-on-insulator on Si substrate

10.1063/1.3686182Journal of Applied Physics1114-JAPI

Erratum: Characterization of thin-film GaAs diodes grown on germanium-on-insulator on Si substrate (Journal of Applied Physics (2012) 111 (044504))

10.1063/1.4818479Journal of Applied Physics1145-JAPI