564 research outputs found
Statistical comparison of ensemble implementations of Grover's search algorithm to classical sequential searches
We compare pseudopure state ensemble implementations, quantified by their
initial polarization and ensemble size, of Grover's search algorithm to
probabilistic classical sequential search algorithms in terms of their success
and failure probabilities. We propose a criterion for quantifying the resources
used by the ensemble implementation via the aggregate number of oracle
invocations across the entire ensemble and use this as a basis for comparison
with classical search algorithms. We determine bounds for a critical
polarization such that the ensemble algorithm succeeds with a greater
probability than the probabilistic classical sequential search. Our results
indicate that the critical polarization scales as N^(-1/4) where N is the
database size and that for typical room temperature solution state NMR, the
polarization is such that the ensemble implementation of Grover's algorithm
would be advantageous for N > 10^2
Housing and Mobility Toolkit for San Mateo County
Since the end of the Great Recession, San Mateo County has attracted new workers at a record rate without building anywhere near enough housing. This jobs-housing imbalance drives the cost of housing up and forces many moderate and lower-income employees and their families out of the County. A lack of access to quality affordable housing in the County and the entire Bay Area along with limited transportation options means that an increased number of employees drive in and out of the County every workday. The resultant congestion, gridlock, and long commutes along with other negative environmental, social, and economic impacts create a major concern for communities in the County and beyond. Clearly, this problem has two distinct but interrelated dimensions: housing development and transportation planning. A select group of Mineta Transportation Institute (MTI) Research Associates worked closely with representatives from the San Mateo County Home for All initiative to help address this challenge by developing a toolkit of successful case studies with a holistic approach to housing development and transportation planning
Is Phaseolus vulgaris Leucoagglutinin (PHA-L) a Useful Marker for Labeling Neural Grafts?
The lectin Phaseolus vulgaris leucoagglutinin
(PHA-L) has come into wide use as an anterograde
neuroanatomical tracer. The ability of this
lectin to fill entire neurons and remain in place
over long periods suggested it might be an ideal
marker for donor cells to be grafted into hosts
for long survival periods. We have used the lectin
PHA-L to mark fetal rat olfactory bulb (OB)
cells prior to grafting into host rat OBs. Hosts
were sacrificed at various times up to 9 weeks after
grafting, and tissue was immunohistochemically
processed for PHA reactivity. After 2 and 4
weeks survival, sparse patterns of labeled cells
were observed within the host OBs. However, after
9 weeks survival, few if any labeled cells were
visible within host tissue. We conclude that
PHA-L may be a less than satisfactory marker
for fetal rat cells (other than astrocytes) which
are to be identified in host tissue after a period of
several weeks
Visual Analytics for Network Security and Critical Infrastructures
A comprehensive analysis of cyber attacks is important for better understanding of their nature and their origin. Providing a sufficient insight into such a vast amount of diverse (and sometimes seemingly unrelated) data is a task that is suitable neither for humans nor for fully automated algorithms alone. Not only a combination of the two approaches but also a continuous reasoning process that is capable of generating a sufficient knowledge base is indispensable for a better understanding of the events. Our research is focused on designing new exploratory methods and interactive visualizations in the context of network security. The knowledge generation loop is important for its ability to help analysts to refine the nature of the processes that continuously occur and to offer them a better insight into the network security related events. In this paper, we formulate the research questions that relate to the proposed solution
Spatial and temporal changes in Bax subcellular localization during anoikis
Bax, a member of the Bcl-2 family, translocates to mitochondria during apoptosis, where it forms oligomers which are thought to release apoptogenic factors such as cytochrome c. Using anoikis as a model system, we have examined spatial and temporal changes in Bax distribution. Bax translocates to mitochondria within 15 min of detaching cells from extracellular matrix, but mitochondrial permeabilization does not occur for a number of hours. The formation of Bax oligomers and perimitochondrial clusters occurs concomitant with caspase activation and loss of mitochondrial membrane potential, before nuclear condensation. Cells can be rescued from apoptosis if they are replated onto extracellular matrix within an hour, whereas cells detached for longer could not. The loss of ability to rescue cells from anoikis occurs after Bax translocation, but before the formation of clusters and cytochrome c release. Our data suggest that Bax regulation occurs at several levels, with formation of clusters a late event, and with critical changes determining cell fate occurring earlier
Quantitative Measurement of Cyber Resilience: Modeling and Experimentation
Cyber resilience is the ability of a system to resist and recover from a
cyber attack, thereby restoring the system's functionality. Effective design
and development of a cyber resilient system requires experimental methods and
tools for quantitative measuring of cyber resilience. This paper describes an
experimental method and test bed for obtaining resilience-relevant data as a
system (in our case -- a truck) traverses its route, in repeatable, systematic
experiments. We model a truck equipped with an autonomous cyber-defense system
and which also includes inherent physical resilience features. When attacked by
malware, this ensemble of cyber-physical features (i.e., "bonware") strives to
resist and recover from the performance degradation caused by the malware's
attack. We propose parsimonious mathematical models to aid in quantifying
systems' resilience to cyber attacks. Using the models, we identify
quantitative characteristics obtainable from experimental data, and show that
these characteristics can serve as useful quantitative measures of cyber
resilience.Comment: arXiv admin note: text overlap with arXiv:2302.04413,
arXiv:2302.0794
An Experimentation Infrastructure for Quantitative Measurements of Cyber Resilience
The vulnerability of cyber-physical systems to cyber attack is well known,
and the requirement to build cyber resilience into these systems has been
firmly established. The key challenge this paper addresses is that maturing
this discipline requires the development of techniques, tools, and processes
for objectively, rigorously, and quantitatively measuring the attributes of
cyber resilience. Researchers and program managers need to be able to determine
if the implementation of a resilience solution actually increases the
resilience of the system. In previous work, a table top exercise was conducted
using a notional heavy vehicle on a fictitious military mission while under a
cyber attack. While this exercise provided some useful data, more and higher
fidelity data is required to refine the measurement methodology. This paper
details the efforts made to construct a cost-effective experimentation
infrastructure to provide such data. It also presents a case study using some
of the data generated by the infrastructure.Comment: 6 pages, 2022 IEEE Military Communications Conference, pp. 855-86
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