134 research outputs found

    A Buffer Stocks Model for Stabilizing Price of Staple Food with Considering the Expectation of Non Speculative Wholesaler

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    This paper is a study of price stabilization in the staple food distribution system. All stakeholders experience market risks due to some possibility causes of price volatility. Many models of price stabilization had been developed by employing several approaches such as floor-ceiling prices, buffer funds, export or import taxes, and subsidies. In the previous researches, the models were expanded to increase the purchasing price for producer and decrease the selling price for consumer. Therefore, the policy can influence the losses for non-speculative wholesaler that is reflected by the descending of selling quantity and ascending of the stocks. The objective of this model is not only to keep the expectation of both producer and consumer, but also to protect non-speculative wholesaler from the undesirable result of the stabilization policy. A nonlinear programming model was addressed to determine the instruments of intervention program. Moreover, the result shows that the wholesaler behavior affects the intervention costs. Index Terms Buffer stocks, Price stabilization, Nonlinear programming, Wholesaler behavior

    Genome-Wide Identification of R2R3-MYB Genes and Expression Analyses During Abiotic Stress in

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    The R2R3-MYB is one of the largest families of transcription factors, which have been implicated in multiple biological processes. There is great diversity in the number of R2R3-MYB genes in different plants. However, there is no report on genome-wide characterization of this gene family in cotton. In the present study, a total of 205 putative R2R3-MYB genes were identified in cotton D genome (Gossypium raimondii), that are much larger than that found in other cash crops with fully sequenced genomes. These GrMYBs were classified into 13 groups with the R2R3-MYB genes from Arabidopsis and rice. The amino acid motifs and phylogenetic tree were predicted and analyzed. The sequences of GrMYBs were distributed across 13 chromosomes at various densities. The results showed that the expansion of the G. Raimondii R2R3-MYB family was mainly attributable to whole genome duplication and segmental duplication. Moreover, the expression pattern of 52 selected GrMYBs and 46 GaMYBs were tested in roots and leaves under different abiotic stress conditions. The results revealed that the MYB genes in cotton were differentially expressed under salt and drought stress treatment. Our results will be useful for determining the precise role of the MYB genes during stress responses with crop improvement

    Search for proton decay into three charged leptons in 0.37 megaton-years exposure of the Super-Kamiokande

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    A search for proton decay into three charged leptons has been performed by using 0.37 Mton⋅years of data collected in Super-Kamiokande. All possible combinations of electrons, muons, and their antiparticles consistent with charge conservation were considered as decay modes. No significant excess of events has been found over the background, and lower limits on the proton lifetime divided by the branching ratio have been obtained. The limits range between 9.2×10^33 and 3.4×10^34 years at 90% confidence level, improving by more than an order of magnitude upon limits from previous experiments. A first limit has been set for the p→Ό^−e^+e^+ mode

    Hyper-Kamiokande Design Report

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    325 pages325 pagesOn the strength of a double Nobel prize winning experiment (Super)Kamiokande and an extremely successful long baseline neutrino programme, the third generation Water Cherenkov detector, Hyper-Kamiokande, is being developed by an international collaboration as a leading worldwide experiment based in Japan. The Hyper-Kamiokande detector will be hosted in the Tochibora mine, about 295 km away from the J-PARC proton accelerator research complex in Tokai, Japan. The currently existing accelerator will be steadily upgraded to reach a MW beam by the start of the experiment. A suite of near detectors will be vital to constrain the beam for neutrino oscillation measurements. A new cavern will be excavated at the Tochibora mine to host the detector. The experiment will be the largest underground water Cherenkov detector in the world and will be instrumented with new technology photosensors, faster and with higher quantum efficiency than the ones in Super-Kamiokande. The science that will be developed will be able to shape the future theoretical framework and generations of experiments. Hyper-Kamiokande will be able to measure with the highest precision the leptonic CP violation that could explain the baryon asymmetry in the Universe. The experiment also has a demonstrated excellent capability to search for proton decay, providing a significant improvement in discovery sensitivity over current searches for the proton lifetime. The atmospheric neutrinos will allow to determine the neutrino mass ordering and, together with the beam, able to precisely test the three-flavour neutrino oscillation paradigm and search for new phenomena. A strong astrophysical programme will be carried out at the experiment that will detect supernova neutrinos and will measure precisely solar neutrino oscillation

    Measurements of the charge ratio and polarization of cosmic-ray muons with the Super-Kamiokande detector

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    We present the results of the charge ratio (RR) and polarization (P0ÎŒP^{\mu}_{0}) measurements using the decay electron events collected from 2008 September to 2022 June by the Super-Kamiokande detector. Because of its underground location and long operation, we performed high precision measurements by accumulating cosmic-ray muons. We measured the muon charge ratio to be R=1.32±0.02R=1.32 \pm 0.02 (stat.+syst.)(\mathrm{stat.}{+}\mathrm{syst.}) at EÎŒcos⁥ΞZenith=0.7−0.2+0.3E_{\mu}\cos \theta_{\mathrm{Zenith}}=0.7^{+0.3}_{-0.2} TeV\mathrm{TeV}, where EÎŒE_{\mu} is the muon energy and ΞZenith\theta_{\mathrm{Zenith}} is the zenith angle of incoming cosmic-ray muons. This result is consistent with the Honda flux model while this suggests a tension with the πK\pi K model of 1.9σ1.9\sigma. We also measured the muon polarization at the production location to be P0ÎŒ=0.52±0.02P^{\mu}_{0}=0.52 \pm 0.02 (stat.+syst.)(\mathrm{stat.}{+}\mathrm{syst.}) at the muon momentum of 0.9−0.1+0.60.9^{+0.6}_{-0.1} TeV/c\mathrm{TeV}/c at the surface of the mountain; this also suggests a tension with the Honda flux model of 1.5σ1.5\sigma. This is the most precise measurement ever to experimentally determine the cosmic-ray muon polarization near 1 TeV/c1~\mathrm{TeV}/c. These measurement results are useful to improve the atmospheric neutrino simulations.Comment: 29 pages, 45 figure

    Search for Cosmic-ray Boosted Sub-GeV Dark Matter using Recoil Protons at Super-Kamiokande

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    We report a search for cosmic-ray boosted dark matter with protons using the 0.37 megaton×\timesyears data collected at Super-Kamiokande experiment during the 1996-2018 period (SKI-IV phase). We searched for an excess of proton recoils above the atmospheric neutrino background from the vicinity of the Galactic Center. No such excess is observed, and limits are calculated for two reference models of dark matter with either a constant interaction cross-section or through a scalar mediator. This is the first experimental search for boosted dark matter with hadrons using directional information. The results present the most stringent limits on cosmic-ray boosted dark matter and exclude the dark matter-nucleon elastic scattering cross-section between 10−33 cm−210^{-33}\text{ cm}^{-2} and 10−27 cm−210^{-27}\text{ cm}^{-2} for dark matter mass from 10 MeV/c2c^2 to 1 GeV/c2c^2.Comment: With 1-page appendi

    Performance of SK-Gd's Upgraded Real-time Supernova Monitoring System

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    Among multi-messenger observations of the next galactic core-collapse supernova, Super-Kamiokande (SK) plays a critical role in detecting the emitted supernova neutrinos, determining the direction to the supernova (SN), and notifying the astronomical community of these observations in advance of the optical signal. On 2022, SK has increased the gadolinium dissolved in its water target (SK-Gd) and has achieved a Gd concentration of 0.033%, resulting in enhanced neutron detection capability, which in turn enables more accurate determination of the supernova direction. Accordingly, SK-Gd's real-time supernova monitoring system (Abe te al. 2016b) has been upgraded. SK_SN Notice, a warning system that works together with this monitoring system, was released on December 13, 2021, and is available through GCN Notices (Barthelmy et al. 2000). When the monitoring system detects an SN-like burst of events, SK_SN Notice will automatically distribute an alarm with the reconstructed direction to the supernova candidate within a few minutes. In this paper, we present a systematic study of SK-Gd's response to a simulated galactic SN. Assuming a supernova situated at 10 kpc, neutrino fluxes from six supernova models are used to characterize SK-Gd's pointing accuracy using the same tools as the online monitoring system. The pointing accuracy is found to vary from 3-7∘^\circ depending on the models. However, if the supernova is closer than 10 kpc, SK_SN Notice can issue an alarm with three-degree accuracy, which will benefit follow-up observations by optical telescopes with large fields of view.Comment: 38 pages, 29 figures, 6 table

    Measurement of the cosmogenic neutron yield in Super-Kamiokande with gadolinium loaded water

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    Cosmic-ray muons that enter the Super-Kamiokande detector cause hadronic showers due to spallation in water, producing neutrons and radioactive isotopes. Those are a major background source for studies of MeV-scale neutrinos and searches for rare events. Since 2020, gadolinium was introduced in the ultra-pure water in the Super-Kamiokande detector to improve the detection efficiency of neutrons. In this study, the cosmogenic neutron yield was measured using data acquired during the period after the gadolinium loading. The yield was found to be (2.76±0.02 (stat.)±0.19 (syst.))×10−4 Ό−1g−1cm2(2.76 \pm 0.02\,\mathrm{(stat.) \pm 0.19\,\mathrm{(syst.)}}) \times 10^{-4}\,\mu^{-1} \mathrm{g^{-1} cm^{2}} at 259 GeV of average muon energy at the Super-Kamiokande detector.Comment: 10 pages, 10 figures, 3 table

    Search for Periodic Time Variations of the Solar 8^8B Neutrino Flux Between 1996 and 2018 in Super-Kamiokande

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    We report a search for time variations of the solar 8^8B neutrino flux using 5,804 live days of Super-Kamiokande data collected between May 31, 1996, and May 30, 2018. Super-Kamiokande measured the precise time of each solar neutrino interaction over 22 calendar years to search for solar neutrino flux modulations with unprecedented precision. Periodic modulations are searched for in a data set comprised of five-day interval solar neutrino flux measurements with a maximum likelihood method. We also applied the Lomb-Scargle method to this data set to compare it with previous reports. The only significant modulation found is due to the elliptic orbit of the Earth around the Sun. The observed modulation is consistent with astronomical data: we measured an eccentricity of (1.53±\pm0.35)\,\%, and a perihelion shift is (−-1.5±\pm13.5)\,days.Comment: 8 pages, 5 figures, 2 tables, and data file: "sksolartimevariation5804d.txt
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