343 research outputs found
The Economic Behavior (Function) of Chinese Militia during the Second World War (Anti-Japanese War)
A militia is an organization that operates like an army but whose members are not professional soldiers. The functions of a militia vary in different periods, particularly during a war, when the militia not only plays a special role in national defense but also plays a unique role in economic production, which has a vital impact on a war scenario. This paper is about the militia in the Shandong Province of China during the Second World War. It explores archival materials to examine the unique economic functions of the militia during this period, and it shows how the militia’s economic role affected the Pacific War
Vertex-based Networks to Accelerate Path Planning Algorithms
Path planning plays a crucial role in various autonomy applications, and RRT*
is one of the leading solutions in this field. In this paper, we propose the
utilization of vertex-based networks to enhance the sampling process of RRT*,
leading to more efficient path planning. Our approach focuses on critical
vertices along the optimal paths, which provide essential yet sparser
abstractions of the paths. We employ focal loss to address the associated data
imbalance issue, and explore different masking configurations to determine
practical tradeoffs in system performance. Through experiments conducted on
randomly generated floor maps, our solutions demonstrate significant speed
improvements, achieving over a 400% enhancement compared to the baseline model.Comment: Accepted to IEEE Workshop on Machine Learning for Signal Processing
(MLSP'2023
Operators which are polynomially isometric to a normal operator
Let be a complex, separable Hilbert space and
denote the algebra of all bounded linear operators
acting on . Given a unitarily-invariant norm on
and two linear operators and in
, we shall say that and are
\emph{polynomially isometric relative to} if for all polynomials . In this paper, we examine to what extent an
operator being polynomially isometric to a normal operator implies that
is itself normal. More explicitly, we first show that if is
any unitarily-invariant norm on , if are polynomially isometric and is normal, then
is normal. We then extend this result to the infinite-dimensional setting
by showing that if are polynomially
isometric relative to the operator norm and is a normal operator whose
spectrum neither disconnects the plane nor has interior, then is normal,
while if the spectrum of is not of this form, then there always exists a
non-normal operator such that and are polynomially isometric.
Finally, we show that if and are compact operators with normal, and
if and are polynomially isometric with respect to the -norm
studied by Chan, Li and Tu, then is again normal.Comment: submitte
Multi-Agent Combinatorial Path Finding with Heterogeneous Task Duration
Multi-Agent Combinatorial Path Finding (MCPF) seeks collision-free paths for
multiple agents from their initial locations to destinations, visiting a set of
intermediate target locations in the middle of the paths, while minimizing the
sum of arrival times. While a few approaches have been developed to handle
MCPF, most of them simply direct the agent to visit the targets without
considering the task duration, i.e., the amount of time needed for an agent to
execute the task (such as picking an item) at a target location. MCPF is
NP-hard to solve to optimality, and the inclusion of task duration further
complicates the problem. This paper investigates heterogeneous task duration,
where the duration can be different with respect to both the agents and
targets. We develop two methods, where the first method post-processes the
paths planned by any MCPF planner to include the task duration and has no
solution optimality guarantee; and the second method considers task duration
during planning and is able to ensure solution optimality. The numerical and
simulation results show that our methods can handle up to 20 agents and 50
targets in the presence of task duration, and can execute the paths subject to
robot motion disturbance
Normal operators with highly incompatible off-diagonal corners
Let be a complex, separable Hilbert space, and
denote the set of all bounded linear operators on
. Given an orthogonal projection
and an operator , we may write
relative to the
decomposition . In
this paper we study the question: for which non-negative integers can we
find a normal operator and an orthogonal projection such that
and ? Complete results are
obtained in the case where , and partial
results are obtained in the infinite-dimensional setting.Comment: submitte
Stable homotopy, 1-dimensional NCCW complexes, and Property (H)
In this paper, we show that the homomorphisms between two unital
one-dimensional NCCW complexes with the same KK-class are stably homotopic,
i.e., with adding on a common homomorphism (with finite dimensional image),
they are homotopic. As a consequence, any one-dimensional NCCW complex has the
Property (H).Comment: Add motivation and backgroun
On Specht's Theorem in UHF C⁎-algebras
The final publication is available at Elsevier via https://doi.org/10.1016/j.jfa.2020.108778 © 2020. This manuscript version is made available under the CC-BY-NC-ND 4.0 licenseSpecht's Theorem states that two matrices A and B in Mn(C) are unitarily equivalent if and only if tr(w(A;A )) = tr(w(B;B )) for all words w(x; y) in two non-commuting variables x and y. In this article we examine to what extent this trace condition characterises approximate unitary equivalence in uniformly hyper nite (UHF) C -algebras. In particular, we show that given two elements a; b of the universal UHF algebra Q which generate C -algebras satisfying the UCT, they are approximately unitarily equivalent if and only if (w(a; a )) = (w(b; b )) for all words w(x; y) in two non-commuting variables (where denotes the unique tracial state on Q), while there exist two elements a; b in the UHF-algebra M21 which fail to be approximately unitarily equivalent despite the fact that they satisfy the trace condition. We also examine a consequence of these results for ampliations of matrices.L.W. Marcoux's research is supported in part by NSERC (Canada); Y.H. Zhang's research is supported in part by National Natural Science Foundation of China (Nos.: 12071174, 11671167), Science and Technology Development Project of Jilin Province (No.: 20190103028JH)
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