263 research outputs found
Off-Policy Evaluation of Ranking Policies under Diverse User Behavior
Ranking interfaces are everywhere in online platforms. There is thus an ever
growing interest in their Off-Policy Evaluation (OPE), aiming towards an
accurate performance evaluation of ranking policies using logged data. A
de-facto approach for OPE is Inverse Propensity Scoring (IPS), which provides
an unbiased and consistent value estimate. However, it becomes extremely
inaccurate in the ranking setup due to its high variance under large action
spaces. To deal with this problem, previous studies assume either independent
or cascade user behavior, resulting in some ranking versions of IPS. While
these estimators are somewhat effective in reducing the variance, all existing
estimators apply a single universal assumption to every user, causing excessive
bias and variance. Therefore, this work explores a far more general formulation
where user behavior is diverse and can vary depending on the user context. We
show that the resulting estimator, which we call Adaptive IPS (AIPS), can be
unbiased under any complex user behavior. Moreover, AIPS achieves the minimum
variance among all unbiased estimators based on IPS. We further develop a
procedure to identify the appropriate user behavior model to minimize the mean
squared error (MSE) of AIPS in a data-driven fashion. Extensive experiments
demonstrate that the empirical accuracy improvement can be significant,
enabling effective OPE of ranking systems even under diverse user behavior.Comment: KDD2023 Research trac
Effective theory for universal seesaw model and FCNC
We study the quark sector of the universal seesaw model with SU(2)
SU(2) .The model incorporates the seesaw mechanism
with the vector-like quarks (VLQs). The purpose of this work is to study the
model with the effective theory. After integrating the heavy five VLQs, we
derive the effective theory with four up-type quark and three down type quark.
In this work, the FCNC of Z boson for top quark and top quark is
derived.Comment: 4 pages, Contribution to the proceedings for International Conference
on Kaon Physics 202
Role of PAF Receptor in Proinflammatory Cytokine Expression in the Dorsal Root Ganglion and Tactile Allodynia in a Rodent Model of Neuropathic Pain
BACKGROUND: Neuropathic pain is a highly debilitating chronic pain following damage to peripheral sensory neurons and is often resistant to all treatments currently available, including opioids. We have previously shown that peripheral nerve injury induces activation of cytosolic phospholipase A(2) (cPLA(2)) in injured dorsal root ganglion (DRG) neurons that contribute to tactile allodynia, a hallmark of neuropathic pain. However, lipid mediators downstream of cPLA(2) activation to produce tactile allodynia remain to be determined. PRINCIPAL FINDINGS: Here we provide evidence that platelet-activating factor (PAF) is a potential candidate. Pharmacological blockade of PAF receptors (PAFRs) reduced the development and expression of tactile allodynia following nerve injury. The expression of PAFR mRNA was increased in the DRG ipsilateral to nerve injury, which was seen mainly in macrophages. Furthermore, mice lacking PAFRs showed a reduction of nerve injury-induced tactile allodynia and, interestingly, a marked suppression of upregulation of tumor necrosis factor alpha (TNFalpha) and interleukin-1beta (IL-1beta) expression in the injured DRG, crucial proinflammatory cytokines involved in pain hypersensitivity. Conversely, a single injection of PAF near the DRG of naïve rats caused a decrease in the paw withdrawal threshold to mechanical stimulation in a dose-dependent manner and an increase in the expression of mRNAs for TNFalpha and IL-1beta, both of which were inhibited by pretreatment with a PAFR antagonist. CONCLUSIONS: Our results indicate that the PAF/PAFR system has an important role in production of TNFalpha and IL-1beta in the DRG and tactile allodynia following peripheral nerve injury and suggest that blocking PAFRs may be a viable therapeutic strategy for treating neuropathic pain
Displacement-noise-free interferometeric gravitational-wave detector using unidirectional neutrons with four speeds
For further gravitational wave (GW) detections, it is significant to invent a
technique to reduce all kinds of mirror displacement noise dominant at low
frequencies for ground-based detectors. The neutron displacement-noise-free
interferometer (DFI) is one of the tools to reduce all the mirror displacement
noise at lower frequencies. In this paper, we describe a further simplified
configuration of a neutron DFI in terms of neutron incidence direction. In the
new configuration, neutrons enter the interferometer with unidirectional
incidence at four speeds as opposed to two bidirectional incidences of opposite
directions at two speeds as reported previously. This simplification of the
neutron DFI is significant for proof-of-principle experiments
Scaling the stimulated emission of polarization-entangled photons using passive optical components
Bright sources of polarization-entangled photon pairs are essential
components for quantum information technologies. In general, it is necessary to
introduce a resonator that combines active optical components such as an
electric optical modulator to enhance the stimulated emission of
polarization-entangled photons. It is technically difficult to perform the time
series operation to output the stimulated entangled photons in the resonator by
synchronizing laser pulses. In this paper, we propose a scheme to scale up the
stimulated emission of polarization-entangled photon pairs using a resonator
with only passive optical components. We show the theoretical aspects of the
scheme and also perform a proof-of-principle experimental demonstration of the
scheme in a double-pass configuration.Comment: 8 pages, 6 figures, Physical Review A to be publishe
Space Environment Effects of Ionizing Radiation on Seed Germination and Growth
An initial limited set of tests of germination rate and seed growth in a controlled environment have identified statistically significant differences between control samples and seed flown in a Russian LEO research flight. Most significantly, average seed germination of space borne seeds was 2 days less than the 6 days for the control seeds. Modification of the seed coat leading to enhanced rate of water uptake, as a result of radiation from the space environment or abrasion due to launch vibrations, is hypothesized to cause early germination. High school students will conduct growth tests on seeds exposed to simulated space environments. The effects of ionizing radiation up to 1 kGy are being studied using a biological exposure test chamber designed by Tsukuba students used in the USU MPG Space Survivability Test (SST) chamber. The SST is a test facility designed to mimic space environments to test environmental-induced modifications to small satellites, or in this case, biological samples. Additional seeds will be exposed to a vibration profile on a shaker table designed to simulate the extreme conditions during flight. Understanding observed space environment effects are important in design of long duration missions, such as to Mars, where food growth is essential.
* Supported by USU STARS! GEAR UP partnership. # Partially funded by Japan Student Services Organizatio
Optimization of quantum noise in space gravitational-wave antenna DECIGO with optical-spring quantum locking considering mixture of vacuum fluctuations in homodyne detection
Quantum locking using optical spring and homodyne detection has been devised
to reduce quantum noise that limits the sensitivity of DECIGO, a space-based
gravitational wave antenna in the frequency band around 0.1 Hz for detection of
primordial gravitational waves. The reduction in the upper limit of energy
density from to
, as inferred from recent observations, necessitates
improved sensitivity in DECIGO to meet its primary science goals. To accurately
evaluate the effectiveness of this method, this paper considers a detection
mechanism that takes into account the influence of vacuum fluctuations on
homodyne detection. In addition, an advanced signal processing method is
devised to efficiently utilize signals from each photodetector, and design
parameters for this configuration are optimized for the quantum noise. Our
results show that this method is effective in reducing quantum noise, despite
the detrimental impact of vacuum fluctuations on its sensitivity.Comment: 12 pages, 5 figure
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