Lattice-Based Dual Receiver Encryption and More

Dual receiver encryption (DRE), proposed by Diament et al. at ACM CCS 2004, is a special extension notion of public-key encryption, which enables two independent receivers to decrypt a ciphertext into a same plaintext. This primitive is quite useful in designing combined public key cryptosystems and denial of service attack-resilient protocols. Up till now, a series of DRE schemes are constructed from bilinear pairing groups and lattices. In this work, we introduce a construction of lattice-based DRE. Our scheme is indistinguishable against chosen-ciphertext attacks (IND-CCA) from the standard Learning with Errors (LWE) assumption with a public key of bit-size about $2nm\log q$, where $m$ and $q$ are small polynomials in $n$. Additionally, for the DRE notion in the identity-based setting, identity-based DRE (IB-DRE), we also give a lattice-based IB-DRE scheme that achieves chosen-plaintext and adaptively chosen identity security based on the LWE assumption with public parameter size about $(2\ell +1)nm\log q$, where $\ell$ is the bit-size of the identity in the scheme

Comparative analysis and characterization of the gut microbiota of four farmed snakes from southern China

Background The gut microbiota plays an important role in host immunity and metabolic homeostasis. Although analyses of gut microbiotas have been used to assess host health and foster disease prevention and treatment, no comparative comprehensive study, assessing gut microbiotas among several species of farmed snake, is yet available. In this study, we characterized and compared the gut microbiotas of four species of farmed snakes (Naja atra, Ptyas mucosa, Elaphe carinata, and Deinagkistrodon acutus) using high-throughput sequencing of the 16S rDNA gene in southern China and tested whether there was a relationship between gut microbiotal composition and host species. Results A total of 629 operational taxonomic units across 22 samples were detected. The five most abundant phyla were Bacteroidetes, Proteobacteria, Firmicutes, Fusobacteria, and Actinobacteria, while the five most abundant genera were Bacteroides, Cetobacterium, Clostridium, Plesiomonas, and Paeniclostridium. This was the first report of the dominance of Fusobacteria and Cetobacterium in the snake gut. Our phylogenetic analysis recovered a relatively close relationship between Fusobacteria and Bacteroidetes. Alpha diversity analysis indicated that species richness and diversity were highest in the gut microbiota of D. acutus and lowest in that of E. carinata. Significant differences in alpha diversity were detected among the four farmed snake species. The gut microbiotas of conspecifics were more similar to each other than to those of heterospecifics. Conclusion This study provides the first comparative study of gut microbiotas among several species of farmed snakes, and provides valuable data for the management of farmed snakes. In farmed snakes, host species affected the species composition and diversity of the gut microbiota

A new species of Boulenophrys from central Hunan Province, China (Anura: Megophryidae)

Abstract We re-examined the megophryinid population from Mt. Hengshan, Hunan Province, China previously identified as Boulenophrys brachykolos (under the name Megophrys brachykolos). Based on newly obtained molecular data, this population appears to be an independent lineage with a relatively distant phylogenetic relationship to B. brachykolos sensu stricto. Furthermore, this population exhibits distinct morphological characteristics that distinguish it from all its congeners. Therefore, we propose to recognize the Hengshan population of B. brachykolos as a new species, Boulenophrys hengshanensis sp. nov. described herein

Preprocess-then-NTT Technique and Its Applications to KYBER and NEWHOPE

The Number Theoretic Transform (NTT) provides efficient algorithm for multiplying large degree polynomials. It is commonly used in cryptographic schemes that are based on the hardness of the Ring Learning With Errors problem (RLWE), which is a popular basis for post-quantum key exchange, encryption and digital signature. To apply NTT, modulus q should satisfy that q = 1 mod 2n, RLWE-based schemes have to choose an oversized modulus, which leads to excessive bandwidth. In this work, we present “Preprocess-then-NTT (PtNTT)” technique which weakens the limitation of modulus q, i.e., we only require q = 1 mod n or q = 1 mod n/2. Based on this technique, we provide new parameter settings for KYBER and NEWHOPE (two NIST candidates). In these new schemes, we can reduce public key size and ciphertext size at a cost of very little efficiency loss

Moderate relative size of covered and non-covered structures of artificial reef enhances the sheltering effect on reef fish

Identifying the relationship between fish aggregations and artificial reefs (ARs) is important for optimizing reef structures and protecting marine resources subjected to external disturbance. Yet, knowledge remains limited of how the distribution of fish is affected by shelter availability provided by different AR structures. Here, we tested the effects of two structural attributes on the distribution of a benthic juvenile reef fish (fat greenling, Hexagrammos otakii). We used a laboratory mesocosm experiment with a simplified reef unit that was made of covered structure and non-covered structure. The covered structure was defined as the area inside ARs that provided effective shelter. The non-covered structure was defined as the area along the edge of ARs, which attracts fish but has lower sheltering effects. Four scenarios of two orthogonal structural attributes contained in a reef unit were implemented: size of covered structure (small shelter versus large shelter) and size of non-covered structure (small edge versus large edge), forming three size ratios of shelters to edges (low, medium, and high). The sheltering effects of the four scenarios were evaluated based on changes to the distribution patterns of fish under disturbance. We found that the reef with a large shelter had a better sheltering effect than the reef with a small shelter, but was limited by its small edge, especially when fish density was high. In contrast, the sheltering effect of the reef with a small shelter was limited by its large edge compared to the small edge. Thus, a moderate shelter-edge ratio enhanced the ability of juvenile fat greenling to elude external disturbance. Our findings highlight the importance of quantifying how the structural composition of reefs affects fish distributions, providing guidance to optimize AR structures

Research on Inverse Kinematics Program Optimization of 6R Decoupled Robot

According to complex analytic formula for the six degrees of freedom decoupled robot, a detailed analysis of the six degrees of freedom decoupled robot analytic formula of export process, as well the causes of multiple solutions. The method of increasing the local variables to avoid processor running the same statement repeatedly is proposed. The method to find the most frequency formula appeared in analytic solution replaced with local variables facilitate the use of loop to reduce the amount of code. It effectively reduces the computation time, optimize the computing process. Finally, taking PUMA560-like robot as an example, the calculation result is verified and simulated in Robotics Toolbox of MATLAB

Robust Tracking Based on Failure Recovery

Object tracking is a issue in the domain of computer visual, most of current state-of-art approaches for visual tracking adapt tracking-by-detection, using detection to address tracking problem. While suitable for cases when the object is always in the sense and these algorithms always results in failures and can’t track back after failure. This paper we propose a tracking method based on failure recovery. After we choose an object to tracking in the first frame, the object is tracked by improved optical flow method forward and backward in time then compute the distance between these two trajectories. While the distance larger then threshold tracking likely to fail, but the latest object model return by detector will re-initialize the tracker. Tracking an object on camera video approve our approach can work at 20fps with long-time robustness. DOI : http://dx.doi.org/10.11591/telkomnika.v12i2.4214 

Description and phylogeny of a new prostomatid, Metacystis similis nov. spec. (Protista, Ciliophora) from the East China Sea

Zhang, Xiumei, Ji, Daode, Zhang, Qianqian, Li, Chenghua (2015): Description and phylogeny of a new prostomatid, Metacystis similis nov. spec. (Protista, Ciliophora) from the East China Sea. Zootaxa 4033 (4): 584-592, DOI: 10.11646/zootaxa.4033.4.