100 research outputs found

    UPIR: Toward the Design of Unified Parallel Intermediate Representation for Parallel Programming Models

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    The complexity of heterogeneous computing architectures, as well as the demand for productive and portable parallel application development, have driven the evolution of parallel programming models to become more comprehensive and complex than before. Enhancing the conventional compilation technologies and software infrastructure to be parallelism-aware has become one of the main goals of recent compiler development. In this paper, we propose the design of unified parallel intermediate representation (UPIR) for multiple parallel programming models and for enabling unified compiler transformation for the models. UPIR specifies three commonly used parallelism patterns (SPMD, data and task parallelism), data attributes and explicit data movement and memory management, and synchronization operations used in parallel programming. We demonstrate UPIR via a prototype implementation in the ROSE compiler for unifying IR for both OpenMP and OpenACC and in both C/C++ and Fortran, for unifying the transformation that lowers both OpenMP and OpenACC code to LLVM runtime, and for exporting UPIR to LLVM MLIR dialect.Comment: Typos corrected. Format update

    Tree-livestock interaction promotes nutrient shift and influences plant species richness in orchards

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    Orchards are traditional agroforestry elements in agricultural landscapes and valuable for nature conservation in Europe. However, their diversity is endangered due to farmland intensification or abandonment. Grazing management promotes plant species diversity but grazers are suspected to harm trees through debarking. We studied 42 orchards within the Rhenish uplands (Germany) and compared horses, cattle and sheep grazing. We analysed how grassland diversity is promoted by the presence of trees and modified by grazing management, as well as how grazers may impact trees. Plant species richness benefited from tree presence, but was not affected by tree-cover and only slightly by grazer species, whereas grazing intensity showed significant negative effects. All grazer species significantly increased recent debarking in the absence of individual tree-protection. Therefore, maintaining species diversity and long-term tree persistence in orchards does not primarily depend upon grazer species, but more especially on grazing intensity and tree-protection

    GSK3β Is Involved in JNK2-Mediated β-Catenin Inhibition

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    We have recently reported that mitogen-activated protein kinase (MAPK) JNK1 downregulates beta-catenin signaling and plays a critical role in regulating intestinal homeostasis and in suppressing tumor formation. This study was designed to determine whether JNK2, another MAPK, has similar and/or different functions in the regulation of beta-catenin signaling.We used an in vitro system with manipulation of JNK2 and beta-catenin expression and found that activated JNK2 increased GSK3beta activity and inhibited beta-catenin expression and transcriptional activity. However, JNK2-mediated downregulation of beta-catenin was blocked by the proteasome inhibitor MG132 and GSK3beta inhibitor lithium chloride. Moreover, targeted mutations at GSK3beta phosphorylation sites (Ser33 and Ser37) of beta-catenin abrogated JNK2-mediated suppression of beta-catenin. In vivo studies further revealed that JNK2 deficiency led to upregulation of beta-catenin and increase of GSK3-beta phosphorylation in JNK2-/- mouse intestinal epithelial cells. Additionally, physical interaction and co-localization among JNK2, beta-catenin and GSK3beta were observed by immunoprecipitation, mammalian two-hybridization assay and confocal microscopy, respectively.In general, our data suggested that JNK2, like JNK1, interacts with and suppresses beta-catenin signaling in vitro and in vivo, in which GSK3beta plays a key role, although previous studies have shown distinct functions of JNK1 and JNK2. Our study also provides a novel insight into the crosstalk between Wnt/beta-catenin and MAPK JNKs signaling

    Dynamic Graph Representation with Knowledge-aware Attention for Histopathology Whole Slide Image Analysis

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    Histopathological whole slide images (WSIs) classification has become a foundation task in medical microscopic imaging processing. Prevailing approaches involve learning WSIs as instance-bag representations, emphasizing significant instances but struggling to capture the interactions between instances. Additionally, conventional graph representation methods utilize explicit spatial positions to construct topological structures but restrict the flexible interaction capabilities between instances at arbitrary locations, particularly when spatially distant. In response, we propose a novel dynamic graph representation algorithm that conceptualizes WSIs as a form of the knowledge graph structure. Specifically, we dynamically construct neighbors and directed edge embeddings based on the head and tail relationships between instances. Then, we devise a knowledge-aware attention mechanism that can update the head node features by learning the joint attention score of each neighbor and edge. Finally, we obtain a graph-level embedding through the global pooling process of the updated head, serving as an implicit representation for the WSI classification. Our end-to-end graph representation learning approach has outperformed the state-of-the-art WSI analysis methods on three TCGA benchmark datasets and in-house test sets. Our code is available at https://github.com/WonderLandxD/WiKG.Comment: Accepted by CVPR 202

    Cold Model Investigations of a High Temperature Looping Process in a Dual Circulating Fluidized Bed System

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    The Calcium Looping process is a promising post-combustion CO2 capture technology. A 200 kWth Dual Circulating Fluidized Bed has been built at IFK, University of Stuttgart. Tests were carried out on a hydrodynamically scaled cold model. Operating parameters have been varied, while the suitability of the 200 kWth design has been prove

    Strongly Unforgeable Certificateless Signature Resisting Attacks from Malicious-But-Passive KGC

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    In digital signature, strong unforgeability requires that an attacker cannot forge a new signature on any previously signed/new messages, which is attractive in both theory and practice. Recently, a strongly unforgeable certificateless signature (CLS) scheme without random oracles was presented. In this paper, we firstly show that the scheme fails to achieve strong unforgeability by forging a new signature on a previously signed message under its adversarial model. Then, we point out that the scheme is also vulnerable to the malicious-but-passive key generation center (MKGC) attacks. Finally, we propose an improved strongly unforgeable CLS scheme in the standard model. The improved scheme not only meets the requirement of strong unforgeability but also withstands the MKGC attacks. To the best of our knowledge, we are the first to prove a CLS scheme to be strongly unforgeable against the MKGC attacks without using random oracles

    CrowdBC: A blockchain-based decentralized framework for crowdsourcing

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    Crowdsourcing systems which utilize the human intelligence to solve complex tasks have gained considerable interest and adoption in recent years. However, the majority of existing crowdsourcing systems rely on central servers, which are subject to the weaknesses of traditional trust-based model, such as single point of failure. They are also vulnerable to distributed denial of service (DDoS) and Sybil attacks due to malicious users involvement. In addition, high service fees from the crowdsourcing platform may hinder the development of crowdsourcing. How to address these potential issues has both research and substantial value. In this paper, we conceptualize a blockchain-based decentralized framework for crowdsourcing named CrowdBC, in which a requester’s task can be solved by a crowd of workers without relying on any third trusted institution, users’ privacy can be guaranteed and only low transaction fees are required. In particular, we introduce the architecture of our proposed framework, based on which we give a concrete scheme. We further implement a software prototype on Ethereum public test network with real-world dataset. Experiment results show the feasibility, usability and scalability of our proposed crowdsourcing system

    GMHL: Generalized Multi-Hop Locks for Privacy-Preserving Payment Channel Networks

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    Payment channel network (PCN), not only improving the transaction throughput of blockchain but also realizing cross-chain payment, is a very promising solution to blockchain scalability problem. Most existing PCN constructions focus on either atomicity or privacy properties. Moreover, they are built on specific scripting features of the underlying blockchain such as HTLC or are tailored to several signature algorithms like ECDSA and Schnorr. In this work, we devise a Generalized Multi-Hop Locks (GMHL) based on adaptor signature and randomizable puzzle, which supports both atomicity and privacy preserving(unlinkability). We instantiate GMHL with a concrete design that relies on a Guillou-Quisquater-based adaptor signature and a novel designed RSA-based randomizable puzzle. Furthermore, we present a generic PCN construction based on GMHL, and formally prove its security in the universal composability framework. This construction only requires the underlying blockchain to perform signature verification, and thus can be applied to various (non-/Turing-complete) blockchains. Finally, we simulate the proposed GMHL instance and compare with other protocols. The results show that our construction is efficient comparable to other constructions while remaining the good functionalities
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