391 research outputs found
Coherent control of a flux qubit by phase-shifted resonant microwave pulses
The quantum state of a flux qubit was successfully pulse-controlled by using
a resonant microwave. We observed Ramsey fringes by applying a pair of
phase-shifted pi/2 microwave pulses without introducing detuning. With this
method, the qubit state can be rotated on an arbitrary axis in the x-y plane of
the Bloch sphere in a rotating frame. We obtained a qubit signal from a
coherent oscillation with an angular velocity of up to 2pi*11.4 Grad/s. In
combination with Rabi pulses, this method enables us to achieve full control of
single qubit operation. It also offers the possibility of orders of magnitude
increases in the speed of the arbitrary unitary gate operation.Comment: 3 pages, 3 figure
Accounting for measurement error in uncertainty modeling and decision-making using indicator kriging and p -field simulation: application to a dioxin contaminated site
In many environmental studies spatial variability is viewed as the only source of uncertainty while measurement errors tend to be ignored. This article presents an indicator kriging-based approach to account for measurement errors in the modeling of uncertainty prevailing at unsampled locations. Probability field simulation is then used to assess the probability that the average pollutant concentration within remediation units exceeds a regulatory threshold, and probability maps are used to identify hazardous units that need to be remediated. This approach is applied to two types of dioxin data (composite and single spoon samples) with different measurement errors which were collected at the Piazza Road dioxin site, an EPA Superfund site located in Missouri. A validation study shows that the proportion of contaminated soil cores provides a reasonable probability threshold to identify hazardous remediation units. When a lower probability threshold is chosen, the total remediation costs are unreasonably high while false negatives are unacceptably frequent for a higher probability threshold. The choice of this threshold becomes critical as the sampling density decreases. Copyright © 2002 John Wiley & Sons, Ltd.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/35237/1/545_ftp.pd
Analysis of Changes in Soil Water Content under Subsurface Drip Irrigation Using Ground Penetrating Radar
Abstract: In arid or semi-arid regions high-performance irrigation systems are necessary to minimize the amount of water used for agriculture purposes. Among common irrigation systems, subsurface irrigation is known to increase the water use efficiency by decreasing the water loss from the ground surface. For effective design and management of the subsurface irrigation systems, non-destructive methods to observe changes in water contents in soils are essential. Ground penetrating radar (GPR), one of the geophysical methods for subsurface measurement, has been used to observe subsurface water contents non-destructively. The main objective of this study was to investigate whether or not changes in soil water content distributions under subsurface irrigation can be observed using GPR. In this study, laboratory experiments were conducted using a soil lysimeter (120 cm × 75 cm × 60 cm) filled with river sands. An irrigation pipe was placed at a depth of 23 cm to supply water at a given head for 60 minutes. A GPR system with 1000 MHz central frequency was used in this study. GPR common offset (CO) data were collected during and after irrigation. CO profile data (radagram) show reflections from wetting fronts around the irrigation pipe. Vertical distributions of water contents at the center were then estimated from two-way travel time of EM waves. This study demonstrates that GPR can be used to observe changes in water contents due to subsurface irrigation
Hard to "tune in": neural mechanisms of live face-to-face interaction with high-functioning autistic spectrum disorder
Persons with autism spectrum disorders (ASD) are known to have difficulty in eye contact (EC). This may make it difficult for their partners during face to face communication with them. To elucidate the neural substrates of live inter-subject interaction of ASD patients and normal subjects, we conducted hyper-scanning functional MRI with 21 subjects with autistic spectrum disorder (ASD) paired with typically-developed (normal) subjects, and with 19 pairs of normal subjects as a control. Baseline EC was maintained while subjects performed real-time joint-attention task. The task-related effects were modeled out, and inter-individual correlation analysis was performed on the residual time-course data. ASD-Normal pairs were less accurate at detecting gaze direction than Normal-Normal pairs. Performance was impaired both in ASD subjects and in their normal partners. The left occipital pole (OP) activation by gaze processing was reduced in ASD subjects, suggesting that deterioration of eye-cue detection in ASD is related to impairment of early visual processing of gaze. On the other hand, their normal partners showed greater activity in the bilateral occipital cortex and the right prefrontal area, indicating a compensatory workload. Inter-brain coherence in the right IFG that was observed in the Normal-Normal pairs (Saito et al., 2010) during EC diminished in ASD-Normal pairs. Intra-brain functional connectivity between the right IFG and right superior temporal sulcus (STS) in normal subjects paired with ASD subjects was reduced compared with in Normal-Normal pairs. This functional connectivity was positively correlated with performance of the normal partners on the eye-cue detection. Considering the integrative role of the right STS in gaze processing, inter-subject synchronization during EC may be a prerequisite for eye cue detection by the normal partner
Neural Basis of Psychological Growth following Adverse Experiences: A Resting-State Functional MRI Study
Over the past decade, research on the aftereffects of stressful or traumatic events has emphasized the negative outcomes from these experiences. However, the positive outcomes deriving from adversity are increasingly being examined, and such positive changes are described as posttraumatic growth (PTG). To investigate the relationship between basal whole-brain functional connectivity and PTG, we employed resting-state functional magnetic resonance imaging and analyzed the neural networks using independent component analysis in a sample of 33 healthy controls. Correlations were calculated between the network connectivity strength and the Posttraumatic Growth Inventory (PTGI) score. There were positive associations between the PTGI scores and brain activation in the rostral prefrontal cortex and superior parietal lobule (SPL) within the left central executive network (CEN) (respectively, r = 0.41, p < 0.001; r = 0.49, p < 0.001). Individuals with higher psychological growth following adverse experiences had stronger activation in prospective or working memory areas within the executive function network than did individuals with lower psychological growth (r = 0.40, p < 0.001). Moreover, we found that individuals with higher PTG demonstrated stronger connectivity between the SPL and supramarginal gyrus (SMG). The SMG is one of the brain regions associated with the ability to reason about the mental states of others, otherwise known as mentalizing. These findings suggest that individuals with higher psychological growth may have stronger functional connectivity between memory functions within the CEN and social functioning in the SMG, and that their better sociality may result from using more memory for mentalizing during their daily social interactions
Refractory Organic Solute Decomposition in Water using Microwave Plasma
金沢大学理工研究域サステナブルエネルギー研究センタ
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