The mission of Korea Superconducting Tokamak Advanced Research (KSTAR)project is to develop an advanced steady-state superconducting tokamak for establishing a scientificand technological basis for an attractive fusio...The mission of Korea Superconducting Tokamak Advanced Research (KSTAR)project is to develop an advanced steady-state superconducting tokamak for establishing a scientificand technological basis for an attractive fusion reactor. Because one of the KSTAR mission is toachieve a steady-state operation, the use of superconducting coils is an obvious choice for themagnet system. The KSTAR superconducting magnet system consists of 16 Toroidal Field (TF) coils and14 Poloidal Field (PF) coils. Internally-cooled Cable-In-Conduit Conductors (CICC) are put into usein both the TF and PF coil systems. The TF coil system provides a field of 3.5 T at the plasmacenter and the PF coil system is able to provide a flux swing of 17 V-sec. The major achievement inKSTAR magnet-system development includes the development of CICC, the development of a full-size TFmodel coil, the development of a coil system for background magnetic-field generation , theconstruction of a large-scale superconducting magnet and CICC test facility. TF and PF coils are inthe stage of fabrication to pave the way for the scheduled completion of KSTAR by the end of 2006.展开更多
We present a novel motion control technique for microrobot clusters to exploit the characteristics of the ultrasonic field.The method comprises two steps,i.e.,introducing an ultrasonic actuation(UA)linear model for th...We present a novel motion control technique for microrobot clusters to exploit the characteristics of the ultrasonic field.The method comprises two steps,i.e.,introducing an ultrasonic actuation(UA)linear model for three-dimensional(3D)locomotion and controlling the topological charge(TC)in the ultrasonic vortex for microrobot clustering.Here,the TC is a controllable parameter for the expansion and contraction of the pressure null space inside the vortex.We present a TC control method to cluster sporadically distributed microrobots in a specific workspace.To validate the concept,a UA system composed of 30 ultrasonic transducers with 1 MHz frequency is fabricated,and the characteristics of the generated acoustic pressure field are analyzed through simulations.Subsequently,the performances of the adaptive controller for precise 3D locomotion and the TC control method for clustering are evaluated.Finally,the UA technology,which performs both clustering and locomotion in a complex manner,is validated with a gelatin phantom in an in-vitro environment.展开更多
We present a search strategy for both Dirac and Majorana sterile neutrinos from the purely leptonic decays of W^±→e^±e^±μ ν and μ^±^±e ν at the 14 TeV LHC. The discovery and exclusion lim...We present a search strategy for both Dirac and Majorana sterile neutrinos from the purely leptonic decays of W^±→e^±e^±μ ν and μ^±^±e ν at the 14 TeV LHC. The discovery and exclusion limits for sterile neutrinos are shown using both the Cut-and-Count（CC） and Multi-Variate Analysis（MVA） methods. We also discriminate between Dirac and Majorana sterile neutrinos by exploiting a set of kinematic observables which differ between the Dirac and Majorana cases. We find that the MVA method, compared to the more common CC method, can greatly enhance the discovery and discrimination limits. Two benchmark points with sterile neutrino mass m N =20 GeV and 50 GeV are tested. For an integrated luminosity of 3000 fb^-1, sterile neutrinos can be found with 5σ significance if heavy-to-light neutrino mixings ｜U_（Ne）｜^2~｜U_（Nμ）｜^2~10^-6, while Majorana vs. Dirac discrimination can be reached if at least one of the mixings is of order 10^-5.展开更多
The universality of the weak interactions can be tested in semileptonic b→c transitions,and in particular in the ratios R（D＊） ≡ Γ（B → D（＊）τν）/Γ（B → D＊lν）（where 1 = μ or e）.Due to the recent diff...The universality of the weak interactions can be tested in semileptonic b→c transitions,and in particular in the ratios R（D＊） ≡ Γ（B → D（＊）τν）/Γ（B → D＊lν）（where 1 = μ or e）.Due to the recent differences between the experimental measurements of these observables by Ba Bar,Belle and LHCb on the one hand and the Standard Model predicted values on the other hand,we study the predicted ratios R（D＊）=Γ（B→D＊τ＋＂missing＂）/Γ（B→D（＊）lν）in scenarios with an additional sterile heavy neutrino of mass ～1 Ge V.Further,we evaluate the newly defined ratio R（0）≡Γ（B→τ＋＂missing＂）/Γ（B→μν） in such scenarios,in view of the future possibilities of measuring the quantity at Belle-Ⅱ.展开更多
基金The project supported by the Korea Ministry of Science and Technology under the KSTAR Project
文摘The mission of Korea Superconducting Tokamak Advanced Research (KSTAR)project is to develop an advanced steady-state superconducting tokamak for establishing a scientificand technological basis for an attractive fusion reactor. Because one of the KSTAR mission is toachieve a steady-state operation, the use of superconducting coils is an obvious choice for themagnet system. The KSTAR superconducting magnet system consists of 16 Toroidal Field (TF) coils and14 Poloidal Field (PF) coils. Internally-cooled Cable-In-Conduit Conductors (CICC) are put into usein both the TF and PF coil systems. The TF coil system provides a field of 3.5 T at the plasmacenter and the PF coil system is able to provide a flux swing of 17 V-sec. The major achievement inKSTAR magnet-system development includes the development of CICC, the development of a full-size TFmodel coil, the development of a coil system for background magnetic-field generation , theconstruction of a large-scale superconducting magnet and CICC test facility. TF and PF coils are inthe stage of fabrication to pave the way for the scheduled completion of KSTAR by the end of 2006.
基金Project supported by the Korea Health Technology Development R&D Project through the Korea Health Industry Development Institute(KHIDI)funded by the Ministry of Health&Welfare,Republic of Korea(No.HI19C0642)the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(No.2023R1A2C2003086)。
文摘We present a novel motion control technique for microrobot clusters to exploit the characteristics of the ultrasonic field.The method comprises two steps,i.e.,introducing an ultrasonic actuation(UA)linear model for three-dimensional(3D)locomotion and controlling the topological charge(TC)in the ultrasonic vortex for microrobot clustering.Here,the TC is a controllable parameter for the expansion and contraction of the pressure null space inside the vortex.We present a TC control method to cluster sporadically distributed microrobots in a specific workspace.To validate the concept,a UA system composed of 30 ultrasonic transducers with 1 MHz frequency is fabricated,and the characteristics of the generated acoustic pressure field are analyzed through simulations.Subsequently,the performances of the adaptive controller for precise 3D locomotion and the TC control method for clustering are evaluated.Finally,the UA technology,which performs both clustering and locomotion in a complex manner,is validated with a gelatin phantom in an in-vitro environment.
基金Supported by the International Postdoctoral Exchange Fellowship Program(No.90 Document of OCPC,2015)the NRF grant funded by the Korean government of the MEST(No.2016R1D1A1A02936965)+2 种基金Chile grants Fondecyt No.1130617Conicyt ACT 1406PIA/Basal FB0821
文摘We present a search strategy for both Dirac and Majorana sterile neutrinos from the purely leptonic decays of W^±→e^±e^±μ ν and μ^±^±e ν at the 14 TeV LHC. The discovery and exclusion limits for sterile neutrinos are shown using both the Cut-and-Count（CC） and Multi-Variate Analysis（MVA） methods. We also discriminate between Dirac and Majorana sterile neutrinos by exploiting a set of kinematic observables which differ between the Dirac and Majorana cases. We find that the MVA method, compared to the more common CC method, can greatly enhance the discovery and discrimination limits. Two benchmark points with sterile neutrino mass m N =20 GeV and 50 GeV are tested. For an integrated luminosity of 3000 fb^-1, sterile neutrinos can be found with 5σ significance if heavy-to-light neutrino mixings ｜U_（Ne）｜^2~｜U_（Nμ）｜^2~10^-6, while Majorana vs. Dirac discrimination can be reached if at least one of the mixings is of order 10^-5.
基金support by FONDECYT(Chile)(1130599)supported in part by the NRF grant funded by the Korean government of the MEST(2016R1D1A1A02936965)
文摘The universality of the weak interactions can be tested in semileptonic b→c transitions,and in particular in the ratios R（D＊） ≡ Γ（B → D（＊）τν）/Γ（B → D＊lν）（where 1 = μ or e）.Due to the recent differences between the experimental measurements of these observables by Ba Bar,Belle and LHCb on the one hand and the Standard Model predicted values on the other hand,we study the predicted ratios R（D＊）=Γ（B→D＊τ＋＂missing＂）/Γ（B→D（＊）lν）in scenarios with an additional sterile heavy neutrino of mass ～1 Ge V.Further,we evaluate the newly defined ratio R（0）≡Γ（B→τ＋＂missing＂）/Γ（B→μν） in such scenarios,in view of the future possibilities of measuring the quantity at Belle-Ⅱ.
