8,672 research outputs found
Analog, hybrid, and digital simulation
Analog, hybrid, and digital computerized simulation technique
Reports on Hybrid-computer Hardware
Hybrid computer and differential analyzer design and development for university instruction progra
Hybrid computer Monte-Carlo techniques
Hybrid analog-digital computer systems for Monte Carlo method application
Measuring the universal synchronization properties of coupled oscillators across the Hopf instability
When a driven oscillator loses phase-locking to a master oscillator via a
Hopf bifurcation, it enters a bounded-phase regime in which its average
frequency is still equal to the master frequency, but its phase displays
temporal oscillations. Here we characterize these two synchronization regimes
in a laser experiment, by measuring the spectrum of the phase fluctuations
across the bifurcation. We find experimentally, and confirm numerically, that
the low frequency phase noise of the driven oscillator is strongly suppressed
in both regimes in the same way. Thus the long-term phase stability of the
master oscillator is transferred to the driven one, even in the absence of
phase-locking. The numerical study of a generic, minimal model suggests that
such behavior is universal for any periodically driven oscillator near a Hopf
bifurcation point.Comment: 5 pages, 5 figure
A Comparison of Standard One-Step DDA Circular Interpolators with a New Cheap Two-Step Algorithm
We present and study existing digital differential analyzer (DDA) algorithms for circle generation, including an improved two-step DDA algorithm which can be implemented solely in terms of elementary shifts, addition, and subtraction
Techniques and errors in measuring cross- correlation and cross-spectral density functions
Techniques and errors in measuring cross spectral density and cross correlation functions of stationary dynamic pressure dat
Real-Time Dispersion Code Multiple Access (DCMA) for High-Speed Wireless Communications
We model, demonstrate and characterize Dispersion Code Multiple Access (DCMA)
and hence show the applicability of this purely analog and real-time multiple
access scheme to high-speed wireless communications. We first mathematically
describe DCMA and show the appropriateness of Chebyshev dispersion coding in
this technology. We next provide an experimental proof-of-concept in a 2 X 2
DCMA system. Finally,we statistically characterize DCMA in terms of bandwidth,
dispersive group delay swing, system dimension and signal-to-noise ratio
EBF1-deficient bone marrow stroma elicits persistent changes in HSC potential
Crosstalk between mesenchymal stromal cells (MSCs) and hematopoietic stem cells (HSCs) is essential for hematopoietic homeostasis and lineage output. Here, we investigate how transcriptional changes in bone marrow (BM) MSCs result in long-lasting effects on HSCs. Single-cell analysis of Cxcl12-abundant reticular (CAR) cells and PDGFRα+Sca1+ (PαS) cells revealed an extensive cellular heterogeneity but uniform expression of the transcription factor gene Ebf1. Conditional deletion of Ebf1 in these MSCs altered their cellular composition, chromatin structure and gene expression profiles, including the reduced expression of adhesion-related genes. Functionally, the stromal-specific Ebf1 inactivation results in impaired adhesion of HSCs, leading to reduced quiescence and diminished myeloid output. Most notably, HSCs residing in the Ebf1-deficient niche underwent changes in their cellular composition and chromatin structure that persist in serial transplantations. Thus, genetic alterations in the BM niche lead to long-term functional changes of HSCs
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