The chemical recovery of a defaced serial number is a common forensic science practice, however it is not understood how proficient experts perform in correctly identifying recovered serial numbers. ...Understanding the accuracy of experts and how they compare to novices in character recognition can help to establish a baseline for this expertise. In this study an expert-novice comparison assessment was completed involving 118 test plates, each stamped with six randomised alphanumeric characters. The plates were defaced and chemically recovered before being viewed by multiple participants over six time intervals. A total of 3169 character inspections were completed. An assessment of confidence and error rates were calculated for both expert (trained) and novice (untrained) participants. Errors were counted when a participant interpreted a different character to that of the ground truth and believed the result was accurate for reporting. The results showed a similar (2.3 % and 2.4 %) error rate for the cohorts, however a statistical difference in confidence levels was recorded, demonstrating the more conservative nature of experts. This study aims to assist in validating practitioner interpretations, through addressing some forensic science criticisms, such as establishing error rates to routine scientific practices.
•An expert-novice comparison study was completed involving 86 participants from across Australia and New Zealand.•A total of 3169 character inspections were completed.•The results showed a consistent error rate between the two cohorts, but a statistical difference in confidence levels.•This study provides data to assist in validating examiners interpretations of chemically recovered serial numbers.
We consider a random partition of the vertex set of an arbitrary graph that can be sampled using loop-erased random walks stopped at a random independent exponential time of parameter q > 0.The ...related random blocks tend to cluster nodes visited by the random walk-with generator the discrete Laplacianon time scale 1/q, with q being the tuning parameter. We explore the emerging macroscopic structure by analyzing 2-point correlations. To this aim, it is defined an interaction potential between pair of vertices, as the probability that they do not belong to the same block of the random partition. This interaction potential can be seen as an affinity measure for "densely connected nodes" and capture well-separated regions in network models presenting non-homogeneous landscapes. In this spirit, we compute this potential and its scaling limits on a complete graph and on a non-homogeneous weighted version with community structures. For the latter geometry we show a phase-transition for "community detectability" as a function of the tuning parameter and the edge weights.
We show how to compute the probabilities of various connection topologies for uniformly random spanning trees on graphs embedded in surfaces. As an application, we show how to compute the “intensity” ...of the loop-erased random walk in
Z
2
\mathbb {Z}^2
, that is, the probability that the walk from
(
0
,
0
)
(0,0)
to
∞
\infty
passes through a given vertex or edge. For example, the probability that it passes through
(
1
,
0
)
(1,0)
is
5
/
16
5/16
; this confirms a conjecture from 1994 about the stationary sandpile density on
Z
2
\mathbb {Z}^2
. We do the analogous computation for the triangular lattice, honeycomb lattice, and
Z
×
R
\mathbb {Z}\times \mathbb {R}
, for which the probabilities are
5
/
18
5/18
,
13
/
36
13/36
, and
1
/
4
−
1
/
π
2
1/4-1/\pi ^2
respectively.
The ferroelectric field-effect transistors (FeFETs) with HfO2-based ferroelectric layers in the gate stacks are emerging as one of the most promising candidates for the next-generation nonvolatile ...memory devices due to their scalability and compatibility with conventional Si technology. Moreover, owing to the high radiation hardness of the HfO2-based ferroelectric thin films, HfO2-based FeFETs have attracted great interest in the fields of radiation-hard (rad-hard) memory. However, the reliability of their memory states under irradiation, which represents the validity of the stored information, has not been investigated. Here, we focus on the impact of the total ionizing dose (TID) on erased and programmed states of HfO2-based FeFETs. The TID radiation (X-ray) characteristics of erased and programmed HfO2-based FeFETs are characterized using an on-site read operation. Both the erased and programmed states show robust stability under irradiation at a dose rate of 90 rad(Si)/s, and even at 230 rad(Si)/s, only the erased state shows a slight variation. The possible factors contributing to memory state degradation are discussed. Through the analysis of the threshold voltage shift and subthreshold swing evolution, as well as studies of ferroelectric polarization stability under radiation, it is revealed that the erased state degradation is caused by oxide-trapped charges rather than interface degradation or polarization switching. The physical mechanism of the difference in radiation-induced oxide-trapped charges buildup in programmed and erased FeFETs is analyzed to explain different TID radiation characteristics between them. Our work suggests that the HfO2-based FeFETs have great potential in radiation environment applications.
We consider dense graph sequences that converge to a connected graphon and prove that the GHP scaling limit of their uniform spanning trees (USTs) is Aldous' Brownian CRT. Furthermore, we are able to ...extract the precise scaling constant from the limiting graphon. As an example, we can apply this to the scaling limit of the USTs of the Erdös–Rényi sequence (G(n,p))n≥1$$ {\left(G\left(n,p\right)\right)}_{n\ge 1} $$ for any fixed p∈(0,1$$ p\in \left(0,1\right $$, and sequences of dense expanders. A consequence of GHP convergence is that several associated quantities of the spanning trees also converge, such as the height, diameter and law of a simple random walk.
The loop-erased random walk (LERW) in ℤ⁴ is the process obtained by erasing loops chronologically for a simple random walk. We prove that the escape probability of the LERW renormalized by
(
log
n
)
...1
3
converges almost surely and in Lp
for all p > 0. Along the way, we extend previous results by the first author building on slowly recurrent sets. We provide two applications for the escape probability. We construct the two-sided LERW, and we construct a ±1 spin model coupled with the wired spanning forests on ℤ⁴ with the bi-Laplacian Gaussian field on ℝ⁴ as its scaling limit.
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