4,855 research outputs found
CMOS array design automation techniques
The design considerations and the circuit development for a 4096-bit CMOS SOS ROM chip, the ATL078 are described. Organization of the ATL078 is 512 words by 8 bits. The ROM was designed to be programmable either at the metal mask level or by a directed laser beam after processing. The development of a 4K CMOS SOS ROM fills a void left by available ROM chip types, and makes the design of a totally major high speed system more realizable
CMOS array design automation techniques
A low cost, quick turnaround technique for generating custom metal oxide semiconductor arrays using the standard cell approach was developed, implemented, tested and validated. Basic cell design topology and guidelines are defined based on an extensive analysis that includes circuit, layout, process, array topology and required performance considerations particularly high circuit speed
Qualification of a Carbon Analyzer to Support the Defense Waste Processing Facility
The I-O Model 1030 carbon analyzer has been qualified for use at the Defense Waste Processing Facility (DWPF). The qualification was a side-by-side comparison of the Model 1030 system with the currently used Model 1010 Analyzer. This recommendation is based on side-by-side comparisons of the new unit to the currently used Model 1010 analyzer that are presented in this report. The side-by-side testing included standards and process samples. The standards, which were used for instrument calibration verifications in the measurement of total inorganic carbon (TIC) and of total organic carbon (TOC), were traceable back to the National Institute of Standards and Technology. The process samples included TIC analyses of Sludge Receipt and Adjustment Tank samples and TOC analyses for Slurry Mix Evaporator (SME) samples. After the Model 1030 has been used for production reporting, DWPF should consider an investigation into the uncertainties associated with the TOC measurements to determine how far below the 18,916 ppm limit DWPF must control the average of the measurements for a set of SME samples to account for the uncertainties of the measurements from this new analyzer. Based upon the results presented in this report, it is recommended that the Model 1030 carbon analyzer is qualified for use. This recommendation is based on side-by-side comparisons of the new unit to the currently used Model 1010 analyzer that are presented in this report. The side-by-side testing included standards for instrument calibration verifications for TIC and TOC, and process samples. The standards were traceable back to NIST. The process samples included TIC analyses of SRAT Receipt samples and TOC analyses for SME samples. At some point in the future, after the Model 1030 has been used for production reporting, DWPF should consider an investigation into the uncertainties associated with the TOC measurements to determine how far below the 18,916 ppm limit DWPF must control the average of the measurements for a set of SME samples to account for the uncertainties of the measurements from this new analyzer
Noise-enhanced trapping in chaotic scattering
We show that noise enhances the trapping of trajectories in scattering
systems. In fully chaotic systems, the decay rate can decrease with increasing
noise due to a generic mismatch between the noiseless escape rate and the value
predicted by the Liouville measure of the exit set. In Hamiltonian systems with
mixed phase space we show that noise leads to a slower algebraic decay due to
trajectories performing a random walk inside Kolmogorov-Arnold-Moser islands.
We argue that these noise-enhanced trapping mechanisms exist in most scattering
systems and are likely to be dominant for small noise intensities, which is
confirmed through a detailed investigation in the Henon map. Our results can be
tested in fluid experiments, affect the fractal Weyl's law of quantum systems,
and modify the estimations of chemical reaction rates based on phase-space
transition state theory.Comment: 5 pages, 5 figure
Intensity Thresholds and the Statistics of the Temporal Occurrence of Solar Flares
Introducing thresholds to analyze time series of emission from the Sun
enables a new and simple definition of solar flare events, and their
interoccurrence times. Rescaling time by the rate of events, the waiting and
quiet time distributions both conform to scaling functions that are independent
of the intensity threshold over a wide range. The scaling functions are well
described by a two parameter function, with parameters that depend on the phase
of the solar cycle. For flares identified according to the current, standard
definition, similar behavior is found.Comment: 5 pages, 4 figures, revtex
Social work students’ experience and management of countertransference
Countertransference – the emotional reactions that clients trigger in practitioners – can, when not understood or managed, result in unethical conduct and harm to clients, practitioners and the profession. A solid understanding of countertransference theory, insight into one’s countertransference reactions and skills in managing countertransference appropriately are a vital component of ethical and effective social work practice. This paper reports on a small qualitative study among undergraduate social work students. Results reveal that countertransference is indeed experienced by students, but poorly understood and sometimes inappropriately managed. Recommendations for social work education, field instruction and supervision are provided
First passage time for subdiffusion: The nonextensive entropy approach versus the fractional model
We study the similarities and differences between different models concerning
subdiffusion. More particularly, we calculate first passage time (FPT)
distributions for subdiffusion, derived from Greens' functions of nonlinear
equations obtained from Sharma-Mittal's, Tsallis's and Gauss's nonadditive
entropies. Then we compare these with FPT distributions calculated from a
fractional model using a subdiffusion equation with a fractional time
derivative. All of Greens' functions give us exactly the same standard relation
which characterizes subdiffusion
(), but generally FPT's are not equivalent to one another. We will
show here that the FPT distribution for the fractional model is asymptotically
equal to the Sharma--Mittal model over the long time limit only if in the
latter case one of the three parameters describing Sharma--Mittal entropy
depends on , and satisfies the specific equation derived in this paper,
whereas the other two models mentioned above give different FTPs with the
fractional model. Greens' functions obtained from the Sharma-Mittal and
fractional models - for obtained from this particular equation - are very
similar to each other. We will also discuss the interpretation of subdiffusion
models based on nonadditive entropies and the possibilities of experimental
measurement of subdiffusion models parameters.Comment: 12 pages, 8 figure
Uni-directional transport properties of a serpent billiard
We present a dynamical analysis of a classical billiard chain -- a channel
with parallel semi-circular walls, which can serve as a model for a bended
optical fiber. An interesting feature of this model is the fact that the phase
space separates into two disjoint invariant components corresponding to the
left and right uni-directional motions. Dynamics is decomposed into the jump
map -- a Poincare map between the two ends of a basic cell, and the time
function -- traveling time across a basic cell of a point on a surface of
section. The jump map has a mixed phase space where the relative sizes of the
regular and chaotic components depend on the width of the channel. For a
suitable value of this parameter we can have almost fully chaotic phase space.
We have studied numerically the Lyapunov exponents, time auto-correlation
functions and diffusion of particles along the chain. As a result of a
singularity of the time function we obtain marginally-normal diffusion after we
subtract the average drift. The last result is also supported by some
analytical arguments.Comment: 15 pages, 9 figure (19 .(e)ps files
On the eigenvalue spacing distribution for a point scatterer on the flat torus
We study the level spacing distribution for the spectrum of a point scatterer
on a flat torus. In the 2-dimensional case, we show that in the weak coupling
regime the eigenvalue spacing distribution coincides with that of the spectrum
of the Laplacian (ignoring multiplicties), by showing that the perturbed
eigenvalues generically clump with the unperturbed ones on the scale of the
mean level spacing. We also study the three dimensional case, where the
situation is very different.Comment: 25 page
Impact of non-Poisson activity patterns on spreading processes
Halting a computer or biological virus outbreak requires a detailed
understanding of the timing of the interactions between susceptible and
infected individuals. While current spreading models assume that users interact
uniformly in time, following a Poisson process, a series of recent measurements
indicate that the inter-contact time distribution is heavy tailed,
corresponding to a temporally inhomogeneous bursty contact process. Here we
show that the non-Poisson nature of the contact dynamics results in prevalence
decay times significantly larger than predicted by the standard Poisson process
based models. Our predictions are in agreement with the detailed time resolved
prevalence data of computer viruses, which, according to virus bulletins, show
a decay time close to a year, in contrast with the one day decay predicted by
the standard Poisson process based models.Comment: 4 pages, 3 figure
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