8 research outputs found
Uniform multi-agent deployment on a ring
AbstractWe consider two variants of the task of spreading a swarm of agents uniformly on a ring graph. Ant-like oblivious agents having limited capabilities are considered. The agents are assumed to have little memory, they all execute the same algorithm and no direct communication is allowed between them. Furthermore, the agents do not possess any global information. In particular, the size of the ring (n) and the number of agents in the swarm (k) are unknown to them. The agents are assumed to operate on an unweighted ring graph. Every agent can measure the distance to his two neighbors on the ring, up to a limited range of V edges.The first task considered, is dynamical (i.e. in motion) uniform deployment on the ring. We show that if either the ring is unoriented, or the visibility range is less than ân/kâ, this is an impossible mission for the agents. Then, for an oriented ring and Vâ„ân/kâ, we propose an algorithm which achieves the deployment task in optimal time. The second task discussed, called quiescent spread, requires the agents to spread uniformly over the ring and stop moving. We prove that under our model, in which every agent can measure the distance only to his two neighbors, this task is impossible. Subsequently, we propose an algorithm which achieves quiescent but only almost uniform spread.The algorithms we present are scalable and robust. In case the environment (the size of the ring) or the number of agents changes during the run, the swarm adapts and re-deploys without requiring any outside interference
Two-robot source seeking with point measurements
AbstractA source-seeking process for a pair of simple, low capability robots using only point measurements is proposed and analyzed. The robots are assumed to be memoryless, to lack the capability of performing complex computations and to have no direct communication abilities. Their only implicit form of communication is by sensing their relative position and the only response of a robot to the point measurement it makes is by moving to adjust its distance to the other robot according to a predetermined rule. The proposed algorithm is robust: we prove that the algorithm performs correctly even when the robots frequently err due to noisy sensor readings
Complementarity for Dark Sector Bound States
We explore the possibility that bound states involving dark matter particles
could be detected by resonance searches at the LHC, and the generic
implications of such scenarios for indirect and direct detection. We
demonstrate that resonance searches are complementary to mono-jet searches and
can probe dark matter masses above 1 TeV with current LHC data. We argue that
this parameter regime, where the bound-state resonance channel is the most
sensitive probe of the dark sector, arises most naturally in the context of
non-trivial dark sectors with large couplings, nearly-degenerate
dark-matter-like states, and multiple force carriers. The presence of bound
states detectable by the LHC implies a minimal Sommerfeld enhancement that is
appreciable, and potentially also radiative bound state formation in the
Galactic halo, leading to large signals in indirect searches. We calculate
these complementary constraints, which favor either models where the
bound-state-forming dark matter constitutes a small fraction of the total
density, or models where the late-time annihilation is suppressed at low
velocities or late times. We present concrete examples of models that satisfy
all these constraints and where the LHC resonance search is the most sensitive
probe of the dark sector.Comment: 22 pages plus appendices, 10 figures, comments welcom
To SMOTE, or not to SMOTE?
Balancing the data before training a classifier is a popular technique to
address the challenges of imbalanced binary classification in tabular data.
Balancing is commonly achieved by duplication of minority samples or by
generation of synthetic minority samples. While it is well known that balancing
affects each classifier differently, most prior empirical studies did not
include strong state-of-the-art (SOTA) classifiers as baselines. In this work,
we are interested in understanding whether balancing is beneficial,
particularly in the context of SOTA classifiers. Thus, we conduct extensive
experiments considering three SOTA classifiers along the weaker learners used
in previous investigations. Additionally, we carefully discern proper metrics,
consistent and non-consistent algorithms and hyper-parameter selection methods
and show that these have a significant impact on prediction quality and on the
effectiveness of balancing. Our results support the known utility of balancing
for weak classifiers. However, we find that balancing does not improve
prediction performance for the strong ones. We further identify several other
scenarios for which balancing is effective and observe that prior studies
demonstrated the utility of balancing by focusing on these settings
New Physics Searches at Kaon and Hyperon Factories
Rare meson decays are among the most sensitive probes of both heavy and light new physics. Among them, new physics searches using kaons benefit from their small total decay widths and the availability of very large datasets. On the other hand, useful complementary information is provided by hyperon decay measurements. We summarize the relevant phenomenological models and the status of the searches in a comprehensive list of kaon and hyperon decay channels. We identify new search strategies for under-explored signatures, and demonstrate that the improved sensitivities from current and next-generation experiments could lead to a qualitative leap in the exploration of light dark sectors
New Physics Searches at Kaon and Hyperon Factories
Rare meson decays are among the most sensitive probes of both heavy and light new physics. Among them, new physics searches using kaons benefit from their small total decay widths and the availability of very large datasets. On the other hand, useful complementary information is provided by hyperon decay measurements. We summarize the relevant phenomenological models and the status of the searches in a comprehensive list of kaon and hyperon decay channels. We identify new search strategies for under-explored signatures, and demonstrate that the improved sensitivities from current and next-generation experiments could lead to a qualitative leap in the exploration of light dark sectors