2,114 research outputs found
Spectral Decomposition of Missing Transverse Energy at Hadron Colliders
We propose a spectral decomposition to systematically extract information of
dark matter at hadron colliders. The differential cross section of events with
missing transverse energy (MET) can be expressed by a linear combination of
basis functions. In the case of -channel mediator models for dark matter
particle production, basis functions are identified with the differential cross
sections of sub-processes of virtual mediator and visible particle production
while the coefficients of basis functions correspond to dark matter invariant
mass distribution in the manner of the K\"all\'en-Lehmann spectral
decomposition. For a given MET data set and mediator model, we show that one
can differentiate a certain dark matter-mediator interaction from another
through spectral decomposition.Comment: 6+4 pages, 6 figures, PRL versio
Outage-based ergodic link adaptation for fading channels with delayed CSIT
Link adaptation in which the transmission data rate is dynamically adjusted
according to channel variation is often used to deal with time-varying nature
of wireless channel. When channel state information at the transmitter (CSIT)
is delayed by more than channel coherence time due to feedback delay, however,
the effect of link adaptation can possibly be taken away if this delay is not
taken into account. One way to deal with such delay is to predict current
channel quality given available observation, but this would inevitably result
in prediction error. In this paper, an algorithm with different view point is
proposed. By using conditional cdf of current channel given observation, outage
probability can be computed for each value of transmission rate . By
assuming that the transmission block error rate (BLER) is dominated by outage
probability, the expected throughput can also be computed, and can be
determined to maximize it. The proposed scheme is designed to be optimal if
channel has ergodicity, and it is shown to considerably outperform conventional
schemes in certain Rayleigh fading channel model
125 GeV Higgs as a pseudo-Goldstone boson in supersymmetry with vector-like matters
We propose a possibility of the 125 GeV Higgs being a pseudo-Goldstone boson
in supersymmetry with extra vector-like fermions. Higgs mass is obtained from
loops of top quark and vector-like fermions from the global symmetry breaking
scale f at around TeV. The mu, Bmu/mu \sim f are generated from the dynamics of
global symmetry breaking and the Higgs quartic coupling vanishes at f as tan
beta \simeq 1. The relation of msoft \sim with f \sim mu \sim m_soft
\sim TeV is obtained and large mu does not cause a fine tuning for the
electroweak symmetry breaking. The Higgs to di-photon rate can be enhanced from
the loop of uncolored vector-like matters. The stability problem of Higgs
potential with vector-like fermions can be nicely cured by the UV completion
with the Goldstone picture.Comment: 28 pages, 8 figure
List Autoencoder: Towards Deep Learning Based Reliable Transmission Over Noisy Channels
In this paper, we present list autoencoder (listAE) to mimic list decoding
used in classical coding theory. With listAE, the decoder network outputs a
list of decoded message word candidates. To train the listAE, a genie is
assumed to be available at the output of the decoder. A specific loss function
is proposed to optimize the performance of a genie-aided (GA) list decoding.
The listAE is a general framework and can be used with any AE architecture. We
propose a specific architecture, referred to as incremental-redundancy AE
(IR-AE), which decodes the received word on a sequence of component codes with
non-increasing rates. Then, the listAE is trained and evaluated with both IR-AE
and Turbo-AE. Finally, we employ cyclic redundancy check (CRC) codes to replace
the genie at the decoder output and obtain a CRC aided (CA) list decoder. Our
simulation results show that the IR-AE under CA list decoding demonstrates
meaningful coding gain over Turbo-AE and polar code at low block error rates
range.Comment: 6 pages with references and 7 figure
Simplified Successive Cancellation List Decoding of PAC Codes
Polar codes are the first class of structured channel codes that achieve the
symmetric capacity of binary channels with efficient encoding and decoding. In
2019, Arikan proposed a new polar coding scheme referred to as
polarization-adjusted convolutional (PAC)} codes. In contrast to polar codes,
PAC codes precode the information word using a convolutional code prior to
polar encoding. This results in material coding gain over polar code under Fano
sequential decoding as well as successive cancellation list (SCL) decoding.
Given the advantages of SCL decoding over Fano decoding in certain scenarios
such as low-SNR regime or where a constraint on the worst case decoding latency
exists, in this paper, we focus on SCL decoding and present a simplified SCL
(SSCL) decoding algorithm for PAC codes. SSCL decoding of PAC codes reduces the
decoding latency by identifying special nodes in the decoding tree and
processing them at the intermediate stages of the graph. Our simulation results
show that the performance of PAC codes under SSCL decoding is almost similar to
the SCL decoding while having lower decoding latency.Comment: 7 pages, 3 figure
Quantitative Screening of Cervical Cancers for Low-Resource Settings: Pilot Study of Smartphone-Based Endoscopic Visual Inspection After Acetic Acid Using Machine Learning Techniques
Background: Approximately 90% of global cervical cancer (CC) is mostly found in low- and middle-income countries. In most cases, CC can be detected early through routine screening programs, including a cytology-based test. However, it is logistically difficult to offer this program in low-resource settings due to limited resources and infrastructure, and few trained experts. A visual inspection following the application of acetic acid (VIA) has been widely promoted and is routinely recommended as a viable form of CC screening in resource-constrained countries. Digital images of the cervix have been acquired during VIA procedure with better quality assurance and visualization, leading to higher diagnostic accuracy and reduction of the variability of detection rate. However, a colposcope is bulky, expensive, electricity-dependent, and needs routine maintenance, and to confirm the grade of abnormality through its images, a specialist must be present. Recently, smartphone-based imaging systems have made a significant impact on the practice of medicine by offering a cost-effective, rapid, and noninvasive method of evaluation. Furthermore, computer-aided analyses, including image processing-based methods and machine learning techniques, have also shown great potential for a high impact on medicinal evaluations
ProductAE: Toward Deep Learning Driven Error-Correction Codes of Large Dimensions
While decades of theoretical research have led to the invention of several
classes of error-correction codes, the design of such codes is an extremely
challenging task, mostly driven by human ingenuity. Recent studies demonstrate
that such designs can be effectively automated and accelerated via tools from
machine learning (ML), thus enabling ML-driven classes of error-correction
codes with promising performance gains compared to classical designs. A
fundamental challenge, however, is that it is prohibitively complex, if not
impossible, to design and train fully ML-driven encoder and decoder pairs for
large code dimensions. In this paper, we propose Product Autoencoder
(ProductAE) -- a computationally-efficient family of deep learning driven
(encoder, decoder) pairs -- aimed at enabling the training of relatively large
codes (both encoder and decoder) with a manageable training complexity. We
build upon ideas from classical product codes and propose constructing large
neural codes using smaller code components. ProductAE boils down the complex
problem of training the encoder and decoder for a large code dimension and
blocklength to less-complex sub-problems of training encoders and decoders
for smaller dimensions and blocklengths. Our training results show successful
training of ProductAEs of dimensions as large as bits with meaningful
performance gains compared to state-of-the-art classical and neural designs.
Moreover, we demonstrate excellent robustness and adaptivity of ProductAEs to
channel models different than the ones used for training.Comment: arXiv admin note: text overlap with arXiv:2110.0446
Effect of charge-transfer complex on the energy level alignment between graphene and organic molecules
We performed density-functional theory calculations to study the electronic structures at the interfaces between graphene and organic molecules that have been used in organic light-emitting diodes. In terms of work function, graphene itself is not favorable as either anode or cathode for commonly used electron or hole transport molecular species. However, the formation of charge transfer complex on the chemically inert sp(2) carbon surface can provide a particular advantage. Unlike metal surfaces, the graphene surface remains non-bonded to electron-accepting molecules even after electron transfer, inducing an improved Fermi-level alignment with the highest-occupied-molecular-orbital level of the hole-injecting-layer molecules.open1
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