140 research outputs found
Recommended high performance telescope system design for the TianQin project
China is planning to construct a new space-borne gravitational-wave (GW)
observatory, the TianQin project, in which the spaceborne telescope is an
important component in laser interferometry. The telescope is aimed to transmit
laser beams between the spacecrafts for the measurement of the displacements
between proof-masses in long arms. The telescope should have ultra-small
wavefront deviation to minimize noise caused by pointing error, ultra-stable
structure to minimize optical path noise caused by temperature jitter,
ultra-high stray light suppression ability to eliminate background noise. In
this paper, we realize a telescope system design with ultra-stable structure as
well as ultra-low wavefront distortion for the space-based GW detection
mission. The design requirements demand extreme control of high image quality
and extraordinary stray light suppression ability. Based on the primary
aberration theory, the initial structure design of the mentioned four-mirror
optical system is explored. After optimization, the maximum RMS wavefront error
is less than lamda/300 over the full field of view (FOV), which meets the noise
budget on the telescope design. The stray light noise caused by the back
reflection of the telescope is also analyzed. The noise at the position of
optical bench is less than 10-10 of the transmitted power, satisfying the
requirements of space gravitational-wave detection. We believe that our design
can be a good candidate for TianQin project, and can also be a good guide for
the space telescope design in any other similar science project
AB-SIFA: SIFA with Adjacent-Byte Model
Statistical Ineffective Fault Attack (SIFA) has been a threat for implementa-tions of symmetric cryptographic primitives. Unlike Differential Fault At-tacks (DFA) which takes both correct and faulty ciphertexts, SIFA can re-cover the secret key with only correct ciphertexts. The classic SIFA is only effective on fault models with non-uniform distribution of intermediate val-ue. In this paper, we present a new fault model named adjacent-byte model, which describes a non-uniform distribution of relationship between two bytes (i.e. exclusive-or). To the best of our knowledge, it is the first time that this fault model has been proposed. We also show that the adjacent-byte faults can be induced by different fault sources and easy to reproduce. Then a new SIFA attack method called AB-SIFA on symmetric cryptography is proposed. We demonstrate the effectiveness of this new attack by simulating the attack. Finally, our attacks are applied to a software implementations of AES-128 with redundant countermeasure and a hardware AES co-processor, utilizing voltage glitches and clock glitches
Natural variation of RGN1a regulates grain number per panicle in japonica rice
The grain number per panicle (GNP) is an important yield component. Identifying naturally favorable variations in GNP will benefit high-yield rice breeding. Here, we performed a genome-wide association study using a mini-core collection of 266 cultivated rice accessions with deep sequencing data and investigated the phenotype for three years. Three genes, i.e., TOTOU1 (TUT1), Grain height date 7 (Ghd7), and Days to heading 7/Grain height date 7.1/Pseudo-Response Regulator37 (DTH7/Ghd7.1/OsPRR37), which regulate GNP, were found in the quantitative trait loci (QTL) identified in this study. A stable QTL, qGNP1.3, which showed a strong correlation with variations in GNP, was repeatedly detected. After functional and transgenic phenotype analysis, we identified a novel gene, regulator of grain number 1a (RGN1a), which codes for protein kinase, controlling GNP in rice. The RGN1a mutation caused 37.2%, 27.8%, 51.2%, and 25.5% decreases in grain number, primary branch number per panicle, secondary branch number per panicle, and panicle length, respectively. Furthermore, breeding utilization analysis revealed that the additive effects of the dominant allelic variants of RGN1a and DTH7 played a significant role in increasing the grain number per panicle in japonica rice. Our findings enrich the gene pool and provide an effective strategy for the genetic improvement of grain numbers
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