78 research outputs found

    International Competition on Graph Counting Algorithms 2023

    Full text link
    This paper reports on the details of the International Competition on Graph Counting Algorithms (ICGCA) held in 2023. The graph counting problem is to count the subgraphs satisfying specified constraints on a given graph. The problem belongs to #P-complete, a computationally tough class. Since many essential systems in modern society, e.g., infrastructure networks, are often represented as graphs, graph counting algorithms are a key technology to efficiently scan all the subgraphs representing the feasible states of the system. In the ICGCA, contestants were asked to count the paths on a graph under a length constraint. The benchmark set included 150 challenging instances, emphasizing graphs resembling infrastructure networks. Eleven solvers were submitted and ranked by the number of benchmarks correctly solved within a time limit. The winning solver, TLDC, was designed based on three fundamental approaches: backtracking search, dynamic programming, and model counting or #SAT (a counting version of Boolean satisfiability). Detailed analyses show that each approach has its own strengths, and one approach is unlikely to dominate the others. The codes and papers of the participating solvers are available: https://afsa.jp/icgca/.Comment: https://afsa.jp/icgca

    Security Analysis on an El-Gamal-like Multivariate Encryption Scheme Based on Isomorphism of Polynomials

    Get PDF
    Isomorphism of polynomials with two secrets (IP2S) problem was proposed by Patarin et al. at Eurocrypt 1996 and the problem is to find two secret linear maps filling in the gap between two polynomial maps over a finite field. At PQC 2020, Santoso proposed a problem originated from IP2S, which is called block isomorphism of polynomials with circulant matrices (BIPC) problem. The BIPC problem is obtained by linearizing IP2S and restricting secret linear maps to linear maps represented by circulant matrices. Using the commutativity of products of circulant matrices, Santoso also proposed an El-Gamal-like encryption scheme based on the BIPC problem. In this paper, we give a new security analysis on the El-Gamal-like encryption scheme. In particular, we introduce a new attack (called linear stack attack) which finds an equivalent key of the El-Gamal-like encryption scheme by using the linearity of the BIPC problem. We see that the attack is a polynomial-time algorithm and can break some 128-bit proposed parameters of the El-Gamal-like encryption scheme within 10 hours on a standard PC

    Development of concave-convex imaging mirror system for a compact and achromatic full-field x-ray microscope

    Full text link
    Jumpei Yamada, Satoshi Matsuyama, Shuhei Yasuda, Yasuhisa Sano, Yoshiki Kohmura, Makina Yabashi, Tetsuya Ishikawa, and Kazuto Yamauchi "Development of concave-convex imaging mirror system for a compact and achromatic full-field x-ray microscope", Proc. SPIE 10386, Advances in X-Ray/EUV Optics and Components XII, 103860C (6 September 2017); https://doi.org/10.1117/12.2272904

    Development of precision Wolter mirrors for solar x-ray observations

    Full text link
    Taro Sakao, Satoshi Matsuyama, Takumi Goto, Jumpei Yamada, Shuhei Yasuda, Kazuto Yamauchi, Yoshiki Kohmura, Ayumi Kime, Akira Miyake, Tadakazu Maezawa, Hirokazu Hashizume, Yoshinori Suematsu, Noriyuki Narukage, and Shin-nosuke Ishikawa "Development of precision Wolter mirrors for solar x-ray observations", Proc. SPIE 10386, Advances in X-Ray/EUV Optics and Components XII, 103860E (23 August 2017); https://doi.org/10.1117/12.2273507

    Improving Photovoltaic Performance of ZnO Nanowires Based Colloidal Quantum Dot Solar Cells via SnO2 Passivation Strategy

    Get PDF
    Colloidal quantum dot solar cells (CQDSCs) based on one-dimensional metal oxide nanowires (NWs) as the electron transport layer (ETL) have attracted much attention due to their larger ETL/colloidal quantum dots (CQDs) contact area and longer electron transport length than other structure CQDSCs, such as planar CQDSCs. However, it is known that defect states in NWs would increase the recombination rate because of the high surface area of NWs. Here, the defect species on the ZnO NWs' surface which resulted in the surface recombination and SnO2 passivation effects were investigated. Comparing with the solar cells using pristine ZnO NWs, the CQDSCs based on SnO2 passivated ZnO NW electrodes exhibited a beneficial band alignment to charge separation, and the interfacial recombination at the ZnO/CQD interface was reduced, eventually resulting in a 40% improvement of power conversion efficiency (PCE). Overall, these findings indicate that surface passivation and the reduction of deep level defects in ETLs could contribute to improving the PCE of CQDSCs

    CNVs in Three Psychiatric Disorders

    Get PDF
    BACKGROUND: We aimed to determine the similarities and differences in the roles of genic and regulatory copy number variations (CNVs) in bipolar disorder (BD), schizophrenia (SCZ), and autism spectrum disorder (ASD). METHODS: Based on high-resolution CNV data from 8708 Japanese samples, we performed to our knowledge the largest cross-disorder analysis of genic and regulatory CNVs in BD, SCZ, and ASD. RESULTS: In genic CNVs, we found an increased burden of smaller (500 kb) exonic CNVs in SCZ/ASD. Pathogenic CNVs linked to neurodevelopmental disorders were significantly associated with the risk for each disorder, but BD and SCZ/ASD differed in terms of the effect size (smaller in BD) and subtype distribution of CNVs linked to neurodevelopmental disorders. We identified 3 synaptic genes (DLG2, PCDH15, and ASTN2) as risk factors for BD. Whereas gene set analysis showed that BD-associated pathways were restricted to chromatin biology, SCZ and ASD involved more extensive and similar pathways. Nevertheless, a correlation analysis of gene set results indicated weak but significant pathway similarities between BD and SCZ or ASD (r = 0.25–0.31). In SCZ and ASD, but not BD, CNVs were significantly enriched in enhancers and promoters in brain tissue. CONCLUSIONS: BD and SCZ/ASD differ in terms of CNV burden, characteristics of CNVs linked to neurodevelopmental disorders, and regulatory CNVs. On the other hand, they have shared molecular mechanisms, including chromatin biology. The BD risk genes identified here could provide insight into the pathogenesis of BD

    Integrative Annotation of 21,037 Human Genes Validated by Full-Length cDNA Clones

    Get PDF
    The human genome sequence defines our inherent biological potential; the realization of the biology encoded therein requires knowledge of the function of each gene. Currently, our knowledge in this area is still limited. Several lines of investigation have been used to elucidate the structure and function of the genes in the human genome. Even so, gene prediction remains a difficult task, as the varieties of transcripts of a gene may vary to a great extent. We thus performed an exhaustive integrative characterization of 41,118 full-length cDNAs that capture the gene transcripts as complete functional cassettes, providing an unequivocal report of structural and functional diversity at the gene level. Our international collaboration has validated 21,037 human gene candidates by analysis of high-quality full-length cDNA clones through curation using unified criteria. This led to the identification of 5,155 new gene candidates. It also manifested the most reliable way to control the quality of the cDNA clones. We have developed a human gene database, called the H-Invitational Database (H-InvDB; http://www.h-invitational.jp/). It provides the following: integrative annotation of human genes, description of gene structures, details of novel alternative splicing isoforms, non-protein-coding RNAs, functional domains, subcellular localizations, metabolic pathways, predictions of protein three-dimensional structure, mapping of known single nucleotide polymorphisms (SNPs), identification of polymorphic microsatellite repeats within human genes, and comparative results with mouse full-length cDNAs. The H-InvDB analysis has shown that up to 4% of the human genome sequence (National Center for Biotechnology Information build 34 assembly) may contain misassembled or missing regions. We found that 6.5% of the human gene candidates (1,377 loci) did not have a good protein-coding open reading frame, of which 296 loci are strong candidates for non-protein-coding RNA genes. In addition, among 72,027 uniquely mapped SNPs and insertions/deletions localized within human genes, 13,215 nonsynonymous SNPs, 315 nonsense SNPs, and 452 indels occurred in coding regions. Together with 25 polymorphic microsatellite repeats present in coding regions, they may alter protein structure, causing phenotypic effects or resulting in disease. The H-InvDB platform represents a substantial contribution to resources needed for the exploration of human biology and pathology
    corecore