DRAGON: A Dialogue-Based Robot for Assistive Navigation with Visual Language Grounding

Persons with visual impairments (PwVI) have difficulties understanding and navigating spaces around them. Current wayfinding technologies either focus solely on navigation or provide limited communication about the environment. Motivated by recent advances in visual-language grounding and semantic navigation, we propose DRAGON, a guiding robot powered by a dialogue system and the ability to associate the environment with natural language. By understanding the commands from the user, DRAGON is able to guide the user to the desired landmarks on the map, describe the environment, and answer questions from visual observations. Through effective utilization of dialogue, the robot can ground the user's free-form descriptions to landmarks in the environment, and give the user semantic information through spoken language. We conduct a user study with blindfolded participants in an everyday indoor environment. Our results demonstrate that DRAGON is able to communicate with the user smoothly, provide a good guiding experience, and connect users with their surrounding environment in an intuitive manner.Comment: Webpage and videos are at https://sites.google.com/view/dragon-wayfinding/hom

Insight on genes affecting tuber development in potato upon <i>Potato spindle tuber viroid</i> (PSTVd) infection

Potato (Solanum tuberosum L) is a natural host of Potato spindle tuber viroid (PSTVd) which can cause characteristic symptoms on developing plants including stunting phenotype and distortion of leaves and tubers. PSTVd is the type species of the family Pospiviroidae, and can replicate in the nucleus and move systemically throughout the plant. It is not well understood how the viroid can affect host genes for successful invasion and which genes show altered expression levels upon infection. Our primary focus in this study is the identification of genes which can affect tuber formation since viroid infection can strongly influence tuber development and especially tuber shape. In this study, we used a large-scale method to identify differentially expressed genes in potato. We have identified defence, stress and sugar metabolism related genes having altered expression levels upon infection. Additionally, hormone pathway related genes showed significant up- or down-regulation. DWARF1/DIMINUTO, Gibberellin 7-oxidase and BEL5 transcripts were identified and validated showing differential expression in viroid infected tissues. Our study suggests that gibberellin and brassinosteroid pathways have a possible role in tuber development upon PSTVd infection

Real-time Monitoring for the Next Core-Collapse Supernova in JUNO

Core-collapse supernova (CCSN) is one of the most energetic astrophysical events in the Universe. The early and prompt detection of neutrinos before (pre-SN) and during the SN burst is a unique opportunity to realize the multi-messenger observation of the CCSN events. In this work, we describe the monitoring concept and present the sensitivity of the system to the pre-SN and SN neutrinos at the Jiangmen Underground Neutrino Observatory (JUNO), which is a 20 kton liquid scintillator detector under construction in South China. The real-time monitoring system is designed with both the prompt monitors on the electronic board and online monitors at the data acquisition stage, in order to ensure both the alert speed and alert coverage of progenitor stars. By assuming a false alert rate of 1 per year, this monitoring system can be sensitive to the pre-SN neutrinos up to the distance of about 1.6 (0.9) kpc and SN neutrinos up to about 370 (360) kpc for a progenitor mass of 30$M_{\odot}$ for the case of normal (inverted) mass ordering. The pointing ability of the CCSN is evaluated by using the accumulated event anisotropy of the inverse beta decay interactions from pre-SN or SN neutrinos, which, along with the early alert, can play important roles for the followup multi-messenger observations of the next Galactic or nearby extragalactic CCSN.Comment: 24 pages, 9 figure

Detection of the Diffuse Supernova Neutrino Background with JUNO

As an underground multi-purpose neutrino detector with 20 kton liquid scintillator, Jiangmen Underground Neutrino Observatory (JUNO) is competitive with and complementary to the water-Cherenkov detectors on the search for the diffuse supernova neutrino background (DSNB). Typical supernova models predict 2-4 events per year within the optimal observation window in the JUNO detector. The dominant background is from the neutral-current (NC) interaction of atmospheric neutrinos with 12C nuclei, which surpasses the DSNB by more than one order of magnitude. We evaluated the systematic uncertainty of NC background from the spread of a variety of data-driven models and further developed a method to determine NC background within 15\% with {\it{in}} {\it{situ}} measurements after ten years of running. Besides, the NC-like backgrounds can be effectively suppressed by the intrinsic pulse-shape discrimination (PSD) capabilities of liquid scintillators. In this talk, I will present in detail the improvements on NC background uncertainty evaluation, PSD discriminator development, and finally, the potential of DSNB sensitivity in JUNO

Potential of Core-Collapse Supernova Neutrino Detection at JUNO

JUNO is an underground neutrino observatory under construction in Jiangmen, China. It uses 20kton liquid scintillator as target, which enables it to detect supernova burst neutrinos of a large statistics for the next galactic core-collapse supernova (CCSN) and also pre-supernova neutrinos from the nearby CCSN progenitors. All flavors of supernova burst neutrinos can be detected by JUNO via several interaction channels, including inverse beta decay, elastic scattering on electron and proton, interactions on C12 nuclei, etc. This retains the possibility for JUNO to reconstruct the energy spectra of supernova burst neutrinos of all flavors. The real time monitoring systems based on FPGA and DAQ are under development in JUNO, which allow prompt alert and trigger-less data acquisition of CCSN events. The alert performances of both monitoring systems have been thoroughly studied using simulations. Moreover, once a CCSN is tagged, the system can give fast characterizations, such as directionality and light curve

JUNO Experiment: Current Status and Physics

The Jiangmen Underground Neutrino Observatory (JUNO) is a 20 kt liquid scintillator (LS) detector under construction 700-m underground in Jiangmen, Guangdong, China, which is expected to be completed in 2023. Its main goal is to determine the neutrino mass ordering (NMO) with the measurement of reactor electron anti-neutrinos from the two adjacent nuclear power plants at a baseline of 53 km. The Taishan Antineutrino Observatory (TAO) detector is located ~30 m from the core of the nuclear power plant, in order to measure the reactor neutrino spectrum, as a reference spectrum for the determination of NMO in JUNO, with resolution better than 2% at 1 MeV. To ensure that the concentration of $^{238}$U and $^{232}$Th in the LS do not exceed the limits for inverse beta decay (IBD) or solar neutrino measurement, the OSIRIS (Online Scintillator Internal Radioactivity Investigation System) pre-detector is installed to monitor the LS of JUNO during the several months of filling. Good sensitivity will be reached for contamination of $^{238}$U/$^{232}$Th, $^{14}$C and $^{210}$Po in the LS. In JUNO, there will be 17,612 20-inch PMTs and 25,600 3-inch PMTs watching at the LS with photocathode coverage of 75.2% and 2.7%, respectively. It is expected that JUNO will have an excellent effective energy resolution of 3% at 1 MeV and an energy nonlinearity uncertainty better than 1%. With 6-years data, the mass ordering can be determined at 3-4σ significant and the precise measurement of oscillation parameters sin$^2θ_{12}$, |∆m$^2_{21}$|, and |∆m$^2_{32}$| will achieve at least 0.6% precision. Besides the main goal, there are many other promising topics of (astro-)particle physics for JUNO. Solar neutrinos will be understood significantly with JUNO’s measurement and the vacuum-matter transition region will be examined. Atmospheric neutrinos measurement will increase the JUNO sensitivity to NMO via a combined analysis. With massive LS, it will be able to detect core-collapse supernova neutrinos of all flavors in multichannels. Low energy threshold down to 10 keV can also be reached for supernova early warning. For the diffuse supernova neutrino background, it is expected to have 2-4 IBD events per year detected with energy above the reactor neutrinos. Geoneutrinos will be detected at a rate of ~400 events per year. The sensitivity of proton decay search will reach 8.34⋅10$^{33}$ years (90% CL) in 10 years of data-taking

JUNO OSIRIS ONLINE TRIGGER

JUNO is a 20 kt liquid scintillator detector under construction in Jiangmen, China, whose goal is to determine the neutrino mass hierarchy. Decay of radioactive isotopes in the liquid scintillator can mimic neutrino signal events. In order to meet the stringent requirements on the radiopurity of the liquid scintillator in JUNO experiment, the OSIRIS pre-detector is being designed to monitor the liquid scintillator during the several months of filling the large volume of JUNO. OSIRIS will contain 20 ton of scintillator and will be equipped with 76 20-inch PMTs. The data acquisition system will have no global hardware trigger: instead, each PMT will provide a data-stream composed of the digitized PMT pulses, each containing a time stamp. Based on the latter, dedicated software will organize these data streams into events by sorting the time stamps and apply trigger logics. To optimize the trigger conditions, physics events are generated from the Geant4-based OSIRIS simulation software. Then the output of photon hits on all PMTs are transferred into our DAQ simulation software where dark counts are also simulated. Afterwards, different trigger conditions are applied in the event builder. This talk will discuss the final trigger setup as a function of $^{14}$C beta-decay event rate and dark rates of PMTs. Our goal is to achieve the optimal trade-off of maintaining a low dark noise event rate with a high trigger efficiency to detect $^{14}$C events

JUNO OSIRIS ONLINE TRIGGER

JUNO is a 20 kt liquid scintillator detector under construction in Jiangmen, China, whose goal is to determine the neutrino mass hierarchy. Decay of radioactive isotopes in the liquid scintillator can mimic neutrino signal events. In order to meet the stringent requirements on the radiopurity of the liquid scintillator in JUNO experiment, the OSIRIS pre-detector is being designed to monitor the liquid scintillator during the several months of filling the large volume of JUNO. OSIRIS will contain 20 ton of scintillator and will be equipped with 76 20-inch PMTs. The data acquisition system will have no global hardware trigger: instead, each PMT will provide a data-stream composed of the digitized PMT pulses, each containing a time stamp. Based on the latter, dedicated software will organize these data streams into events by sorting the time stamps and apply trigger logics. To optimize the trigger conditions, physics events are generated from the Geant4-based OSIRIS simulation software. Then the output of photon hits on all PMTs are transferred into our DAQ simulation software where dark counts are also simulated. Afterwards, different trigger conditions are applied in the event builder. This talk will discuss the final trigger setup as a function of $^{14}$C beta-decay event rate and dark rates of PMTs. Our goal is to achieve the optimal trade-off of maintaining a low dark noise event rate with a high trigger efficiency to detect $^{14}$C events

Trigger Studies for the OSIRIS Pre-detector of JUNO

JUNO is a 20 kt liquid scintillator detector under construction in Jiangmen, China, whose goal is to determine the neutrino mass hierarchy. Its data taking is expected to start in 2022. Decay of radioactive isotopes in the liquid scintillator can mimic neutrino signal events. In order to meet the stringent requirements on the radiopurity of the liquid scintillator, the OSIRIS (Online Scintillator Internal Radioactivity Investigation System) pre-detector is being designed to monitor the liquid scintillator during the several months of filling the large volume of JUNO. OSIRIS will contain 18 ton of scintillator and will be equipped with 76 20-inch PMTs. The data acquisition system will have no global hardware trigger: instead, each PMT will provide a data-stream composed of the digitized PMT pulses, each containing a time stamp. Based on the latter, dedicated software will organize these data streams into events by sorting the time stamps and applying trigger logics. To optimize the trigger conditions, physics events are generated from the Geant4-based OSIRIS simulation software. Then the output of photon hits on all PMTs are transferred into our DAQ simulation software where dark counts are also simulated. Afterwards, different trigger conditions are applied in the event builder software. This poster will show the optimization of the event trigger conditions, for the inner liquid scintillator detector as well as outer water Cherenkov detector, considering the expected rates of different radio-active contaminations, cosmogenic muons, and the PMT dark rates