16 research outputs found

    When Private Blockchain Meets Deterministic Database

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    Private blockchain as a replicated transactional system shares many commonalities with distributed database. However, the intimacy between private blockchain and deterministic database has never been studied. In essence, private blockchain and deterministic database both ensure replica consistency by determinism. In this paper, we present a comprehensive analysis to uncover the connections between private blockchain and deterministic database. While private blockchains have started to pursue deterministic transaction executions recently, deterministic databases have already studied deterministic concurrency control protocols for almost a decade. This motivates us to propose Harmony, a novel deterministic concurrency control protocol designed for blockchain use. We use Harmony to build a new relational blockchain, namely HarmonyBC, which features low abort rates, hotspot resiliency, and inter-block parallelism, all of which are especially important to disk-oriented blockchain. Empirical results on Smallbank, YCSB, and TPC-C show that HarmonyBC offers 2.0x to 3.5x throughput better than the state-of-the-art private blockchains

    Design of Three-Dimensional Virtual Simulation Experiment Platform for Integrated Circuit Course

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    The integrated circuit (IC) is a subject for which researchers need practical experience, but its experiment cost is high, the risk involved is high, and it is not easy to carry out experiments on a large scale. This paper designs a three-dimensional integrated circuit virtual experiment platform based on Unity3d. The platform uses the Unity3d and 3ds Max tools to build a three-dimensional model of instruments, equipment, electronic components, and ultra cleanroom laboratory scenes in an integrated circuit experiment. In addition, it uses C# script to develop the functions and three-dimensional simulation of general virtual instruments and equipment and deploys the experimental website using the frame of the jspxcms open source website. The experimental platform arranges the three-dimensional web file WebGL file in the cloud. Students can use video and text materials to acquire basic IC knowledge at any time and conduct IC virtual experiments safely, efficiently, and without constraints. At present, the platform has been tested and used in teaching and has received high praise and recognition from students

    Analysis of integrated uses of dockless bike sharing and ridesourcing with metros: A case study of Shanghai, China

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    To enhance the last-mile connectivity of metros, transport managers are experimenting with the integration of shared mobility modes, such as dockless bike sharing (DBS) and ridesourcing. To provide theoretical guidance for transport managers, it is imperative to deepen knowledge of the differences between the integration of DBS and ridesourcing with metros. A three-level structure was developed in this study to identify integrated DBS and ridesourcing trips using observed data from DiDi and Mobike in Shanghai, China. The travel characteristics of two identified integrated shared mobility modes were then compared. Finally, negative binomial regression models were built to investigate the factors influencing these two integrated uses. Comparative analysis shows that the travel distance intervals with the highest proportions are 0.5–1.0 km for DBS and 1.0–1.5 km for ridesourcing. In terms of temporal distribution, morning peaks of integrated DBS trips are higher and earlier than those of ridesourcing. In the spatial dimension, integrated DBS and ridesourcing trips are mainly concentrated in the central urban area and suburban areas, respectively. Further examination indicates that the built environment has different impacts on these two integrated uses. These results provide an improved understanding of the seamless integration of shared mobility modes with metros

    Saguaro: Efficient Processing of Transactions in Wide Area Networks using a Hierarchical Permissioned Blockchain

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    The next frontier for the Internet leading by innovations in mobile computing, in particular, 5G, together with blockchains' transparency, immutability, provenance, and authenticity, indicates the potentials of running a new generation of applications on the mobile internet. A 5G-enabled blockchain system is structured as a hierarchy and needs to deal with different challenges such as maintaining blockchain ledger at different spatial domains and various levels of the networks, efficient processing of cross-domain transactions, establishing consensus among heterogeneous nodes, and supporting delay-tolerant mobile transactions. In this paper, we present Saguaro, a hierarchical permissioned blockchain designed specifically for Internet-scale mobile networks. Saguaro benefits from the hierarchical structure of mobile network infrastructure to address the aforementioned challenges. Our extensive experimental results demonstrate the high potential of Saguaro being the first 5G-enabled permissioned blockchain system in the community

    The guiding value of microvascular invasion for treating early recurrent small hepatocellular carcinoma

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    Introduction Hepatocellular carcinoma (HCC) patients with microvascular invasion (MVI) have worse survival. Whether the presence of MVI indicates the necessity of more aggressive locoregional treatments for recurrences remains to be elucidated. Methods We reviewed patients who underwent curative hepatectomy for primary HCC in our institution, and 379 patients with recurrent HCC up to three nodules smaller than 3 cm were enrolled. The Kaplan–Meier method was adopted to compare the secondary recurrence-free survival (sRFS) and post-recurrence survival (PRS) among patients undergoing hepatectomy, RFA and transarterial chemoembolization plus RFA (TACE-RFA). Cox regression analyses were performed to identify independent prognostic factors. Results Both the sRFS and PRS of the MVI (−) group were significantly longer than those of the MVI (+) group (p = 0.001 and 0.011). For patients with MVI (−), no significant difference was found in sRFS or PRS among recurrent HCC patients receiving hepatectomy, RFA or TACE-RFA (p = 0.149 and 0.821). A similar trend was found in patients with MVI (+) (p = 0.851 and 0.960). Further analysis found that TACE-RFA provided better sRFS than hepatectomy or RFA alone in patients with MVI (+) and early recurrence within two years (p = 0.036 and 0.044). Conclusion For HCC patients with MVI (+) and early small recurrence, TACE-RFA could achieve better prognosis than hepatectomy or RFA alone, while RFA alone provided comparable survival benefits compared with hepatectomy or TACE-RFA in other HCC patients with small recurrence
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