关键词：
Introduction;Materials and Methods;Results;Discussion;Conclusion;Abstract;Data Availability;Additional Points;Ethical Approval;Consent;Disclosure;Conflicts of Interests;Authors’ Contributions;Funding Statement;Acknowledgements;Acknowledgments;Supplementary Materials;Reference;Dataset Description;Dataset Files;Abstract;Introduction;Introduction and Materials;Introduction and Methods;Materials;Materials and Methods;Methods;Results;Discussion;Results and Discussion;Discussion and Conclusion;Results and Conclusion;Conclusion;Conclusions;Data Availability;Additional Points;Ethical Approval;Consent;Disclosure;Conflicts of Interest;Authors’ Contributions;Funding Statement;Acknowledgements;Supplementary Materials;References;Appendix;Abbreviations;Preliminaries;Introduction and Preliminaries;Notation;Proof of Theorem;Proofs;Analysis of Results;Examples;Numerical Example;Applications;Numerical Simulation;Model;Model Formulation;Systematic Palaeontology;Nomenclatural Acts;Taxonomic Implications;Experimental;Synthesis;Overview;Characterization;Background;Experimental;Theories;Calculations;Model Verification;Model Implementation;Geographic location;Study Area;Geological setting;Data Collection;Field Testing;Data and Sampling;Dataset;Literature Review;Related Works;Related Work;System Model;Methods and Data;Experimental Results;Results and Analysis;Evaluation;Implementation;Case Presentation;Case Report;Search Terms;Case Description;Case Series;Background;Limitations;Additional Points;Case;Case 1;Case 2 etc.;Concern Details;Retraction Details;Copyright;Related Articles
摘要：
In the Internet of Things (IoT), data sharing security is important to social security. It is a huge challenge to enable more accurate and secure access to data by authorized users. Blockchain access control schemes are mostly one-way access control, which cannot meet the need for ciphertext search, two-way confirmation of users and data, and secure data transmission. Thus, this paper proposes a blockchain-aided searchable encryption-based two-way attribute access control scheme (STW-ABE). The scheme combines ciphertext attribute access control, key attribute access control, and ciphertext search. In particular, two-way access control meets the requirement of mutual confirmation between users and data. The ciphertext search avoids information leakage during transmission, thus improving overall efficiency and security during data sharing. Moreover, user keys are generated by the coalition blockchain. Besides, the ciphertext search and pre-decryption are outsourced to cloud servers, reducing the computing pressure on users and adapting to the needs of lightweight users in the IoT. Security analysis proves that our scheme is secure under a chosen-plaintext attack and a chosen keyword attack. Simulations show that the cost of encryption and decryption, keyword token generation, and ciphertext search of our scheme are preferable.
期刊：
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS,2022年519:28-36 ISSN：0168-583X
通讯作者：
Fei Mao
作者机构：
[Li, Shi-Ming; Mao, Fei; Zhao, Xu-Dong] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.;[Cheng, Guo-Dong] Univ South China, Sch Comp Sci & Technol, Hengyang 421001, Peoples R China.;[Li, Bing-Sheng] Southwest Univ Sci & Technol, State Key Lab Environm Friendly Energy Mat, Mianyang 621010, Sichuan, Peoples R China.;[Mao, Hong] Hunan Inst Sci & Technol, Coll Mech Engn, Yueyang 414006, Hunan, Peoples R China.;[Wang, Feng] Beijing Inst Technol, Sch Phys, Beijing 100081, Peoples R China.
通讯机构：
[Fei Mao] S;School of Nuclear Science and Technology, University of South China, Hengyang 421001, China
关键词：
Electron transfer;Electronic excitation;Excitation threshold;Stopping power
摘要：
The electronic stopping power of Zn for energetic protons is studied by using a nonequilibrium approach based on real-time time-dependent density-functional theory combined with molecular dynamics simulations. We calculated the electronic stopping power of protons traveling along two channeling trajectories depending on the impact parameter and off-channeling trajectories, and revealed the mechanism for d-electron excitation. In the low-velocity range, we reproduced not only the velocity proportionality of the stopping power of Zn for protons, but also the smooth transition between two velocity proportionality regimes, which is ascribed to the gradually increasing efficiency for d-electron excitation. The off-channeling electronic stopping power is in a good agreement with experimental data in the low and middle-velocity regimes. Our results showed that the contribution of d-electron excitation to the electronic stopping is remarkable in the high-velocity regime.
摘要：
Spark Streaming is an extension of the core Spark engine that enables scalable, high-throughput, fault-tolerant stream processing of live data streams. It treats stream as a series of deterministic batches and handles them as regular jobs. However, for a stream job responsible for a batch, data skew (i.e., the imbalance in the amount of data allocated to each reduce task), can degrade the job performance significantly because of load imbalance. In this paper, we propose an improved range partitioner (ImRP) to alleviate the reduce skew for stream jobs in Spark Streaming. Unlike previous work, ImRP does not require any pre-run sampling of input data and generates the data partition scheme based on the intermediate data distribution estimated by the previous batch processing, in which a prediction model EWMA (Exponentially Weighted Moving Average) is adopted. To lighten the data skew, ImRP presents a novel method of calculating the partition borders optimally, and a mechanism of splitting the border key clusters when the semantics of shuffle operators permit. Besides, ImRP considers the integrated partition size and heterogeneity of computing environments when balancing the load among reduce tasks appropriately. We implement ImRP in Spark-3.0 and evaluate its performance on four representative benchmarks: wordCount, sort, pageRank, and LDA. The results show that by mitigating the data skew, ImRP can decrease the execution time of stream jobs substantially compared with some other partition strategies, especially when the skew degree of input batch is serious.
关键词：
Oblivious RAM;Accountability;Group signature;Blockchain;Access control
摘要：
Recently, oblivious random access machine (ORAM) has been widely used to prevent privacy leakage from user's access pattern. However, in multi-user scenarios, the obliviousness property of ORAM facilitates the malicious data modification by unauthorized users, which brings a new security challenge of user accountability to ORAM applications. Moreover, based on our observations, existing user accountability schemes for multi-user ORAM induce the extremely unacceptable overhead in both time and storage. What is worse, it is still inherent the traditional cloud accountability problem that the untrusted cloud server may have misbehavior on storing the outsourced data. In this paper, we focus on the issue that how to do accountability for both malicious users and untrusted cloud server without the independent trusted third party server. To address the above problem, we design and implement a Traceable Oblivious RAM, or T-ORAM for short, a cryptographic system that protects the privacy of users and the integrity of outsourced data based on group signatures. It can detect malicious users quickly by utilizing the traceability property of group signatures, and cost less storage overhead comparing with the existing solutions. Then, we further propose a more secure solution of Blockchain-based Traceable Oblivious RAM (BT-ORAM). Specifically, by introducing the blockchain technology, BT-ORAM can detect the malicious behavior from both malicious users and untrusted cloud server. BT-ORAM is the first accountability work for multi-user ORAM that deal with both malicious users and the untrusted cloud server. Finally, security analysis and experimental results show that our method outperforms the state-of-the-art accountability work for oblivious RAM, S-GORAM, in both security and performance. (C) 2019 Elsevier Inc. All rights reserved.
摘要：
microRNAs (miRNAs) are small and important non-coding RNAs that regulate gene expression in transcriptional and post-transcriptional level by combining with their targets (genes). Predicting miRNA targets is an important problem in biological research. It is expensive and time-consuming to identify miRNA targets by using biological experiments. Many computational methods have been proposed to predict miRNA targets. In this study, we develop a novel method, named miRTRS, for predicting miRNA targets based on a recommendation algorithm. miRTRS can predict targets for an isolated (new) miRNA with miRNA sequence similarity, as well as isolated (new) targets for a miRNA with gene sequence similarity. Furthermore, when compared to supervised machine learning methods, miRTRS does not need to select negative samples. We use 10-fold cross validation and independent datasets to evaluate the performance of our method. We compared miRTRS with two most recently published methods for miRNA target prediction. The experimental results have shown that our method miRTRS outperforms competing prediction methods in terms of AUC and other evaluation metrics.
摘要：
Qutrit is the natural extension of qubit in quantum information processing and has quite a few advantages that outperform qubit. In this paper, we investigate the feasibility of teleportation of an unknown qubit state, as well as an unknown qutrit state using a two-qutrit entangled pair. We show that by carefully constructing the measurement bases, both the qubit and the qutrit can be faithfully teleported from Alice to Bob with a two-qutrit maximally entangled state.
摘要：
International Classification of Diseases (ICD) code is an important label of electronic health record. The automatic ICD code assignment based on the narrative of clinical documents is an essential task which has drawn much attention recently. When Chinese clinical notes are the input corpus, the nature of Chinese brings some issues that need to be considered, such as the accuracy of word segmentation and the representation of single Chinese characters which contain semantics. Taking the lengthy text of patient notes and the representation of Chinese words into account, we present a multilayer attention bidirectional recurrent neural network (MA-BiRNN) model to implement the assignment of disease codes. A hierarchical approach is used to represent the feature of discharge summaries without manual feature engineering. The combination of character level embedding and word level embedding can improve the representation of words. Attention mechanism is introduced into bidirectional long short term memory networks, which helps to solve the performance dropping problem when plain recurrent neural networks encounter long text sequences. The experiment is carried out on a real-world dataset containing 7732 admission records in Chinese and 1177 unique ICD-10 labels. The proposed model achieves 0.639 and 0.766 in F1-score on full-level code and block-level code, respectively. It outperforms the baseline neural network models and achieves the lowest Hamming loss value. Ablation analysis indicates that the multilevel attention mechanism plays a decisive role in the system for dealing with Chinese clinical notes.
作者机构：
[Cheng, G. D.; Yan, S. Y.; Wan, Y. P.] Univ South China, Sch Comp Sci & Technol, Hengyang 421001, Hunan, Peoples R China.;[Cheng, G. D.; Yan, S. Y.] CNNC Key Lab High Trusted Comp, Hengyang 421001, Hunan, Peoples R China.
通讯机构：
[Cheng, GD; Yan, SY] U;Univ South China, Sch Comp Sci & Technol, Hengyang 421001, Hunan, Peoples R China.
关键词：
Defect;Optical properties;Qubit;Spin coherence time
作者机构：
[Liu, Jie; Chen, Mingsong; Liu, Jing; Sun, Haiying; Chen, Xiaohong; Du, Dehui] East China Normal Univ, Shanghai Key Lab Trustworthy Comp, Shanghai 200062, Peoples R China.;[Liu, Jie] Univ South China, Sch Comp Sci & Technol, Hengyang 421001, Peoples R China.;[Zhang, Miaomiao] Tongji Univ, Sch Software Engn, Shanghai 201804, Peoples R China.
通讯机构：
[Liu, Jing] E;[Zhang, Miaomiao] T;East China Normal Univ, Shanghai Key Lab Trustworthy Comp, Shanghai 200062, Peoples R China.;Tongji Univ, Sch Software Engn, Shanghai 201804, Peoples R China.
关键词：
混合系统;开发;证明;微分;分离控制;建模语言;研究人员;精炼
摘要：
Event-B is a widely applied and proof-based language for incremental development via refinement [1]. Hybrid systems exhibit hybrid characteristics of discrete control and real-time continuous behaviors. However, Event-B is a discrete modeling language. It does not support the development of hybrid systems. So, the researchers are currently trying to make the extension of Event-B for the refinement development of hybrid systems [2, 3].
关键词：
Single image super-resolution;Gradient tree boosting;Multi-output regression
摘要：
The learning-based single image super-resolution (SISR) algorithm aims at recovering a high-resolution (HR) image from low-resolution (LR) input. The quality of the HR output mainly depends on the strength of the learning algorithms. Observing that gradient boosting is powerful in dealing with learning problems, we propose a new SISR method based on the gradient boosting framework. First, the boosting framework is extended to the general form of multi-output regression. Then, an error correction approximation is used to sequentially train the boosting trees. The training data for each tree are the pairs of the features of the LR image patches and the negative gradients of the loss function. Meanwhile, shrinkage, a slow learning strategy, is exploited to reduce the risk of overfitting. Finally, all boosting trees are linearly combined to form an accurate predictor. The experimental results verify that our method can generate visually pleasant HR images and achieve accuracy on par with state-of-the-art methods in terms of quantitative evaluation.
摘要：
In medical image practice, it is common to upsample images for better view or subsequent processing, such as image segmentation or registration. The commonly used upsampling methods include bicubic or cubic splines. The shape of interpolation kernels are usually square windows. However, the square kernels are not always optimal since there are a lot of complex local structures in medical images. The interpolated high-resolution pixels should preserve these local structures. In this paper we propose a novel shape-adaptive method for magnetic resonance (MR) images upsampling. First, the optimal shape of interpolation kernel is determined by the classic LPA-ICI algorithm. After then, the high-resolution pixels are fitted by radial basis function. Moreover, in order to synthesize more visually pleasant high-resolution output, the details of the upsampled image are extracted and enhanced, and then added back to the high-resolution image. We test the proposed method on four MR image sets. The experiments validate that the proposed method can produce competitive results with some state-of-the-art methods in both visual effects and quantitative evaluations. In addition, the proposed method is simple and easy to implement.
