470 research outputs found
Electron acceleration with improved Stochastic Differential Equation method: cutoff shape of electron distribution in test-particle limit
We develop a method of stochastic differential equation to simulate electron
acceleration at astrophysical shocks. Our method is based on It\^{o}'s
stochastic differential equations coupled with a particle splitting, employing
a skew Brownian motion where an asymmetric shock crossing probability is
considered. Using this code, we perform simulations of electron acceleration at
stationary plane parallel shock with various parameter sets, and studied how
the cutoff shape, which is characterized by cutoff shape parameter , changes
with the momentum dependence of the diffusion coefficient . In the
age-limited cases, we reproduce previous results of other authors,
. In the cooling-limited cases, the analytical expectation
is roughly reproduced although we recognize deviations to
some extent. In the case of escape-limited acceleration, numerical result fits
analytical stationary solution well, but deviates from the previous asymptotic
analytical formula .Comment: corrected typos, 10 pages, 4 figures, 2 tables, JHEAp in pres
A novel A792D mutation in the CSF1R gene causes hereditary diffuse leukoencephalopathy with axonal spheroids characterized by slow progression
Hereditary diffuse leukoencephalopathy with spheroids (HDLS) is an autosomal dominant white matter disease that causes adult-onset cognitive impairment. The clinical manifestations are a variable combination of personality and behavioral changes, cognitive decline, parkinsonism, spasticity, and epilepsy. In 2012, mutations in the gene encoding colony stimulating factor 1 receptor (CSF1R) were identified as the cause of HDLS. As the numbers of reported mutations are limited, the understanding of whole pathogenesis needs accumulation of disease-causing mutations with detailed clinical descriptions. We describe a Japanese family with autosomal dominant adult-onset cognitive impairment and characteristic white matter lesions. Genetic testing revealed a novel p.A792D mutation in the tyrosine kinase domain of CSF1R in two affected family members. The symptom profile of the present cases mostly matched the previously reported cases, with the notable exceptions of late-onset and long disease duration
Switching Head-Tail Funnel UNITER for Dual Referring Expression Comprehension with Fetch-and-Carry Tasks
This paper describes a domestic service robot (DSR) that fetches everyday
objects and carries them to specified destinations according to free-form
natural language instructions. Given an instruction such as "Move the bottle on
the left side of the plate to the empty chair," the DSR is expected to identify
the bottle and the chair from multiple candidates in the environment and carry
the target object to the destination. Most of the existing multimodal language
understanding methods are impractical in terms of computational complexity
because they require inferences for all combinations of target object
candidates and destination candidates. We propose Switching Head-Tail Funnel
UNITER, which solves the task by predicting the target object and the
destination individually using a single model. Our method is validated on a
newly-built dataset consisting of object manipulation instructions and semi
photo-realistic images captured in a standard Embodied AI simulator. The
results show that our method outperforms the baseline method in terms of
language comprehension accuracy. Furthermore, we conduct physical experiments
in which a DSR delivers standardized everyday objects in a standardized
domestic environment as requested by instructions with referring expressions.
The experimental results show that the object grasping and placing actions are
achieved with success rates of more than 90%.Comment: Accepted for presentation at IROS202
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