240 research outputs found
Synchro: Block-generation Protocol to Synchronously Process Cross-shard Transactions in State Sharding
Traditional blockchains cannot achieve the same transaction throughput as
Web2, so their use cases are limited. Therefore, state sharding has been
proposed to improve transaction throughput by dividing the blockchain network
and managing states and transactions in parallel. However, Nightshade in the
NEAR Protocol, a type of state sharding, provides a rollback protocol to cancel
the generation of blocks containing inconsistent transaction results because
processing cross-shard transactions (CSTXs) in a 2-phase commit may cause state
inconsistency. We present a new attack that interferes with the generation of
new blocks by repeatedly executing CSTXs that certainly causes state
inconsistency, causing continuous rollback. We also propose a block-generation
protocol called Synchro to incorporate all the state changes of each CSTX into
the same block by coordinating the block prior to approving transactions in
each shard. Synchro eliminates the occurrence of the state inconsistency caused
by the CSTXs and the necessity of the rollback protocol. We use zero-knowledge
proof to make Synchro scalable in the global validation phase. Although the
actual overhead of the zero-knowledge proof has not yet been evaluated, we show
that Synchro could achieve the same transaction throughput as Nightshade
theoretically, depending on the future innovations in zero-knowledge proof
techniques
Lightweight High-Speed and High-Force Gripper for Assembly
This paper presents a novel industrial robotic gripper with a high grasping
speed (maximum: 1396 mm/s), high tip force (maximum: 80 N) for grasping, large
motion range, and lightweight design (0.3 kg). To realize these features, the
high-speed section of the quick-return mechanism and load-sensitive
continuously variable transmission mechanism are installed in the gripper. The
gripper is also equipped with a self-centering function. The high grasping
speed and self-centering function improve the cycle time in robotic operations.
In addition, the high tip force is advantageous for stably grasping and
assembling heavy objects. Moreover, the design of the gripper reduce the
gripper's proportion of the manipulator's payload, thus increasing the weight
of the object that can be grasped. The gripper performance was validated
through kinematic and static analyses as well as experimental evaluations. This
paper also presents the analysis of the self-centering function of the
developed gripper
Development and Performance of Kyoto's X-ray Astronomical SOI pixel (SOIPIX) sensor
We have been developing monolithic active pixel sensors, known as Kyoto's
X-ray SOIPIXs, based on the CMOS SOI (silicon-on-insulator) technology for
next-generation X-ray astronomy satellites. The event trigger output function
implemented in each pixel offers microsecond time resolution and enables
reduction of the non-X-ray background that dominates the high X-ray energy band
above 5--10 keV. A fully depleted SOI with a thick depletion layer and back
illumination offers wide band coverage of 0.3--40 keV. Here, we report recent
progress in the X-ray SOIPIX development. In this study, we achieved an energy
resolution of 300~eV (FWHM) at 6~keV and a read-out noise of 33~e- (rms) in the
frame readout mode, which allows us to clearly resolve Mn-K and
K. Moreover, we produced a fully depleted layer with a thickness of
. The event-driven readout mode has already been successfully
demonstrated.Comment: 7pages, 12figures, SPIE Astronomical Telescopes and Instrumentation
2014, Montreal, Quebec, Canada. appears as Proc. SPIE 9147, Space Telescopes
and Instrumentation 2014: Ultraviolet to Gamma Ra
喫煙は小胞体ストレスを惹起し、RhoAの活性化を介してefferocytosisを抑制する
長崎大学学位論文 [学位記番号]博(医歯薬)甲第1295号 [学位授与年月日]令和2年12月2
No association between the sigma receptor type 1 gene and schizophrenia: results of analysis and meta-analysis of case-control studies
BACKGROUND: Several lines of evidence have supported possible roles of the sigma receptors in the etiology of schizophrenia and mechanisms of antipsychotic efficacy. An association study provided genetic evidence that the sigma receptor type 1 gene (SIGMAR1) was a possible susceptibility factor for schizophrenia, however, it was not replicated by a subsequent study. It is necessary to evaluate further the possibility that the SIGMAR1 gene is associated with susceptibility to schizophrenia. METHODS: A case-control association study between two polymorphisms of the SIGMAR1 gene, G-241T/C-240T and Gln2Pro, and schizophrenia in Japanese population, and meta-analysis including present and previous studies. RESULTS: There was no significant association of any allele or genotype of the polymorphisms with schizophrenia. Neither significant association was observed with hebephrenic or paranoid subtype of schizophrenia. Furthermore, a meta-analysis including the present and previous studies comprising 779 controls and 636 schizophrenics also revealed no significant association between the SIGMAR1 gene and schizophrenia. CONCLUSION: In view of this evidence, it is likely that the SIGMAR1 gene does not confer susceptibility to schizophrenia
Synthesis of conjugated polymers via direct C–H/C–Cl coupling reactions using a Pd/Cu binary catalytic system
Direct arylation polycondensation is regarded as an efficient synthetic method for conjugated polymers. This methodology is difficult to apply to dichloroaryl monomers because of the low reactivity of the C–Cl bonds compared to that of the C–Br bonds in dibromoaryl monomers, which have been widely used in direct arylation polycondensation. In this research, direct arylation polycondensation of dichloroaryl monomers was achieved by the use of a Pd/Cu binary catalytic system. Optimisation of the molar ratio of the Pd and Cu catalyst resulted in the formation of high-molecular-weight polymers in good yields. Structural defects of the polymer at the terminal unit were minimised by logical choice of the monomer ratio on the basis of the reaction mechanism. The obtained polymer with relatively low structural defects showed a higher quantum efficiency of photoluminescence and electroluminescence than that of the polymer with irregular terminal structures
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