Yazhou Niu | Searcharxiv

arXiv2024

How does ClinicalTrials.gov Impact Company Innovation?

Pharmaceutical companies may have incentives to exaggerate the therapeutic effects of their developed products during the clinical stage, which endangers the health of patients. To increase transparency in clinical practice, the NIH established ClinicalTrials.gov in 2000, which indicates a significant impact on medicine. However, little evidence shows how ClinicalTrials.gov affects medical enterprises innovation. By identifying the patent application activities through USPTO, Pubmed, and Compustat, we used coherent DID to prove the impact of ClinicalTrials.gov on innovation. We found that the emergence of ClinicalTrials.gov reduced the number of patent applications and led to a shift in RD directions. This effect can also be moderated depending on firm size, probably because small companies are more incentivized to manipulate data. Hence, we suggest agencies could consider wide-ranging influences when formulating open science policies.

econ.GN↗

arXiv2021

SiPM Dynamic Range for CEPC Scintillator-based Electromagnetic Calorimeter

Ahigh-granularity scintillator calorimeter readout with silicon photomultipliers (SiPMs) is an electromagnetic calorimeter (ECAL) candidate for experiments at the Circular Electron Positron Collider (CEPC). A critical design parameter of this ECAL candidate is the dynamic range of the SiPMs. This study investigates the SiPM dynamic range required for the CEPC scintillator ECAL. A model is developed on the basis of the operation principles of SiPMs to describe the response of an SiPM to light pulses within one recovery period by considering the cross-talk effect, photon detection efficiency, and number of pixels. The response curve of a 10000-pixel SiPM predicted by the model is consistent with the measured curve within 2% for an incident light pulse of up to 12000 photons. The intrinsic fluctuations of the SiPM response naturally exist in this model, and the correction of the saturation effect in the SiPM response is investigated. Monte Carlo (MC) simulation shows that the algorithm can restore the response linearity of an SiPM for an incident light pulse in which the number of photons is up to around six times the number of SiPM pixels. The model and correction program are implemented for full simulation of the ZH production Z->vv, H->yy channel to evaluate the impact of the SiPM dynamic range of the CEPC scintillator ECAL on the reconstructed Higgs boson mass and the sensitivity to the Higgs signal in this channel. The results show that the CEPC scintillator ECAL equipped with no less than 4000 SiPM pixels and operated with a light yield of 20 photon-electrons per channel for a single minimum ionizing particle can meet the requirements for Higgs boson precision measurement in the di-photon channel at the CEPC.

physics.ins-det↗

arXiv2020

Optimization study of scintillator shape of electromagnetic calorimeter for Higgs factories

Scintillator-based calorimeters for experiments at Higgs factories (e.g. ILC) demand scintillator designs that can detect sufficient number of photons and have good light yield uniformity, and that they can be easily mass-produced. In order to meet these requirements, scintillator strips with a small dimple has been proposed. In our study, we measure the light yield of a dimple scintillator sample; we then compare the measurements with light tracing simulation using GEANT4. We intend to use our results to propose an optimized scintillator shape.

physics.ins-det↗