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Path Sensitive Fuzzing for Native Applications

IEEE TRANSACTIONS ON DEPENDABLE AND SECURE COMPUTING 2022年第3期19卷 1544-1561页

作者： Gan, Shuitao Zhang, Chao Qin, Xiaojun Tu, xuwen li, Kang Pei, Zhongyu Chen, Zuoning State Key Lab Math Engn & Adv Comp Wuxi Jiangsu Peoples R China Tsinghua Univ Inst Network Sci & Cyberspace Beijing 100084 Peoples R China Beijing Natl Res Ctr Informat Sci & Technol Beijing 100084 Peoples R China Anonymous Univ Beijing Peoples R China

Coverage-guided fuzzing is a widely used and effective solution to find software vulnerabilities. Tracking code coverage and utilizing it to guide fuzzing are crucial to coverage-guided fuzzers. However, tracking full and accurate path coverage is infeasible in practice due to the high instrumentation overhead. Popular fuzzers (e.g., AFL) often use coarse coverage information, e.g., edge hit counts stored in a compact bitmap, to achieve highly efficient greybox testing. Such inaccuracy and incompleteness in coverage introduce serious limitations to fuzzers. First, it causes path collisions, which prevent fuzzers from discovering potential paths that lead to new crashes. More importantly, it prevents fuzzers from making wise decisions on fuzzing strategies. In this article, we propose a coverage sensitive fuzzing solution CollAFL. It mitigates path collisions by providing more accurate coverage information, while still preserving low instrumentation overhead. It also utilizes the coverage information to apply three new fuzzing strategies, promoting the speed of discovering new paths and vulnerabilities. We implemented two variants of this solution, namely CollAFL (based on AFL) and CollAFL-bin (based on AFL-dyninst), to test applications with and without source code respectively, and evaluated them on 24 popular applications. The results showed that path collisions are common, i.e., up to 75 percent of edges could collide with others in some applications. But our solutions CollAFL and CollAFL-bin could reduce the edge collision ratio to nearly zero. Moreover, armed with the three fuzzing strategies, they outperform their counterparts (i.e., AFL and AFL-dyninst) in terms of both code coverage and vulnerability discovery. On average, CollAFL covered 20 percent more program paths, and found 320 percent more unique crashes and 260 percent more bugs than AFL in 200 hours. Moreover, CollAFL-bin covered 15 percent more paths, and found 200 percent more unique crashes and 15

关键词： Fuzzing Computer bugs Instruments Security Grammar Cyberspace Coverage-guided fuzzing path collision bitmap seed selection policy source code binary code

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Optimising maize threshing process with temporal proximity soft actor-critic deep reinforcement learning algorithm

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BIOSYSTEMS ENGINEERING 2024年 248卷 229-239页

作者： Zhang, Qiang Fang, xuwen Gao, Xiaodi Zhang, Jinsong Zhao, Xuelin Yu, Lulu Yu, Chunsheng Zhou, Deyi Zhou, Haigen Zhang, li Wu, Xinling Jilin Univ Coll Biol & Agr Engn Changchun 130022 Peoples R China Jilin Jianzhu Univ Sch Emergency Sci & Engn Changchun 130118 Peoples R China

Maize threshing is a crucial process in grain production, and optimising it is essential for reducing post-harvest losses. This study proposes a model-based temporal proximity soft actor-critic (TP-SAC) algorithm to optimise the maize threshing process in the threshing drum. The proposed approach employs an LSTM model as a real-time predictor of threshing quality, achieving an R2 of 97.17% and 98.43% for damage and unthreshed rates on the validation set. In actual threshing experiments, the LSTM model demonstrates an average error of 5.45% and 3.83% for damage and unthreshed rates. The LSTM model is integrated with the TP-SAC algorithm, acting as the environment with which the TP-SAC interacts, enabling efficient training with limited real-world data. The TPSAC algorithm addresses the temporal correlation in the threshing process by incorporating temporal proximity sampling into the SAC algorithm's experience replay mechanism. TP-SAC outperforms the standard SAC algorithm in the simulated environment, demonstrating better sample efficiency and faster convergence. When deployed in actual threshing operations, the TP-SAC algorithm reduces the damage rate by an average of 0.91% across different feed rates compared to constant control. The proposed TP-SAC algorithm offers a novel and practical approach to optimising the maize threshing process, enhancing threshing quality.

关键词： Threshing quality optimisation Agricultural machinery Machine learning Agricultural automation Sensitivity analysis

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"Twisted" small molecule donors with enhanced intermolecular interactions in the condensed phase towards efficient and thick-film all-small-molecule organic solar cells

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JOURNAL OF MATERIALS CHEMISTRY A 2023年第26期11卷 13984-13993页

作者： Cheng, Xiafei liang, Ziqi liang, Shifeng Zhang, xuwen Xu, Jie Xu, Yan Ni, Wang li, Miaomiao Geng, Yanhou Tianjin Univ Sch Mat Sci & Engn Tianjin Key Lab Mol Optoelect Sci Tianjin 300072 Peoples R China Tianjin Inst Power Sources Sci & Technol Power Sources Lab Tianjin 300384 Peoples R China Sinopec Beijing Res Inst Chem Ind Co Ltd Beijing 100013 Peoples R China Joint Sch Natl Univ Singapore & Tianjin Univ Int Campus Tianjin Univ Fuzhou 350207 Peoples R China

How to achieve high crystallinity and suitable phase scale simultaneously from the perspective of molecular engineering remains a long-standing challenge for all-small-molecule organic solar cells (ASM-OSCs). Herein, two small molecule donors, named DRTT-2Se (with two alkylselenophenyl chains) and DRTT-6Se (with six alkylselenophenyl chains), were designed and synthesized by introducing "twisted" backbones and building units with strong intermolecular interactions. The "twisted" skeletons of the molecules can suppress the molecular crystallization and avoid excessive aggregation during the film forming process, while the strong intermolecular interactions of the building units can encourage the formation of ordered molecular packing and nanoscale phase separation via post-treatments. Owing to the enhanced intermolecular interactions induced by alkylselenophenyl side chains, DRTT-2Se and DRTT-6Se with a "twisted" structure displayed more ordered pi-pi packing, and retained the similar nanoscale microstructures in the blend films in comparison to the "twisted" molecule with alkylthiophenyl side chains (DRTT-T), yielding improved hole transport and reduced charge recombination in OSCs. In addition, the alkylselenophenyl substituted molecules showed higher HOMO energy levels, which caused the larger HOMO offset to drive exciton dissociation, but did not increase the energy loss. As a result, the ASM-OSCs based on the selenophene-containing donors exhibited higher FF and J(sc), and similar V-oc, yielding superior PCEs (14.79% and 15.03%) compared to the DRTT-T based device (13.37%). More importantly, the appropriate film morphology made the device efficiency of DRTT-2Se and DRTT-6Se less sensitive to the thickness of active layers. This study provides some implications in designing small molecule donors with suitable crystallization behavior towards high-performance ASM-OSCs.

关键词： Molecules

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Research on sound source localization based on sound sensor 4

Research on sound source localization based on sound sensor

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4rth International Conference on Applied Mathematics, Modelling, and Intelligent Computing, CAMMIC 2024

作者： Jin, Hailei Wang, xuwen Huang, Kun Xiong, Xiaomin Zhang, Minshu li, Jiang Xinyu Power Supply Branch of State Grid jiangxi Power Co. Ltd. Xinyu338000 China Shanghai University of Electric Power Shanghai200090 China

ISBN: (纸本)9781510681637

Nowadays, most of the 10 kV distribution network cable lines are laid underground in the form of direct burial or casing, and the cable is cut off by the construction machinery, resulting in the accident of line tripping. In the construction of urban construction, third-party external forces such as manual excavation, mechanical excavation and illegal invasion will cause serious damage to underground cables. Therefore, it is of great engineering application value to develop cable marking piles with sound source localization function and find the location of damage points in time. In order to improve the accuracy and effectiveness of positioning, but also to achieve rapid positioning of the source of damage, this paper is based on the sound sensor, using its flexibility, efficiency and timeliness, by controlling the number and location of the sound sensor, combined with the sound intensity to locate the sound source. At the same time, the sound sensor is connected with the number and position of the marking pile, and the traditional cable marking pile is improved to accurately locate the damage source in time. © 2024 SPIE.

关键词： Excavation

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2D-Material-Based Volatile and Nonvolatile Memristive Devices for Neuromorphic Computing

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ACS MATERIALS LETTERS 2023年第4期5卷 1109-1135页

作者： Xia, xuwen Huang, Wen Hang, Pengjie Guo, Tao Yan, Yong Yang, Jianping Yang, Deren Yu, Xuegong li, Xing'ao Nanjing Univ Posts & Telecommun NJUPT New Energy Technol Engn Lab Jiangsu Prov Nanjing 210023 Peoples R China Nanjing Univ Posts & Telecommun NJUPT Sch Sci Nanjing 210023 Peoples R China Zhejiang Univ State Key Lab Silicon Mat Hangzhou 310027 Zhejiang Peoples R China Zhejiang Univ Sch Mat Sci & Engn Hangzhou 310027 Zhejiang Peoples R China Univ Waterloo Waterloo Inst Nanotechnol Ctr Adv Mat Joining Dept Mech & Mechatron Engn Waterloo ON N2L 3G1 Canada Henan Normal Univ Sch Phys Henan Key Lab Photovolta Mat Xinxiang 453007 Peoples R China Zhejiang Univ Sci & Technol Sch Sci Hangzhou 310027 Peoples R China

Neuromorphic computing can process large amounts of information in parallel and provides a powerful tool to solve the von Neumann bottleneck. Constructing an artificial neural network (ANN) is a common means to realize neuromorphic computing, which has exhibited potential applications in pattern recognition, complex sensing, and other areas. Reservoir computing (RC), which is another approach to realize neuromorphic computing, has shown some progress and attracted researchers' attention. Neuromorphic computing can be generally implemented by fabricating memristive array systems. 2D-material-based memristive systems and their applications in ANN and RC have been investigated substantially in recent years due to the unique properties of these systems, such as atomic-level thickness and high carrier mobility. In this Review, we first discuss the volatility and nonvolatility properties of memristive devices and their applications in ANN and RC. Second, 2D materials that can be used to fabricate these devices are introduced, and their classification, physical properties, and preparation methods are presented. Third, we discuss the working mechanisms of 2D-material-based synaptic devices, the mimicked synaptic functions, and the applications of these devices in neuromorphic computing through ANN and RC. Lastly, the performance, progress, and future development directions of 2D-material-based synaptic devices are analyzed. This work systematically investigates the status of 2D-material-based synaptic devices and promotes their utilization in neuromorphic computing.

关键词： Electrical conductivity Layers Memristors Polarization Two dimensional materials

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结核性“树芽征”CT表现与病理结果对照分析

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实用医学影像杂志 2019年第3期20卷 278-280页

作者：李旭文李颖上海市松江区泗泾医院放射科 201600 内蒙古民族大学第二临床医学院(内蒙古林业总医院)医学影像科

目的提高对结核性“树芽征”CT影像特征的认识水平,明确CT所见的结核性“树芽征”相对应的病理意义。方法对照分析7例经手术治疗的继发性肺结核患者的CT影像表现及相对应的病理结果,复习文献。结果结核性“树芽征”的“树状”部分对应... 详细信息

目的提高对结核性“树芽征”CT影像特征的认识水平,明确CT所见的结核性“树芽征”相对应的病理意义。方法对照分析7例经手术治疗的继发性肺结核患者的CT影像表现及相对应的病理结果,复习文献。结果结核性“树芽征”的“树状”部分对应于小叶内炎性细支气管,而“芽状”部分对应充满了炎性物质的比相应的细支气管粗大的肺泡管,“树芽状”病变包括腔内干酪或支气管内、支气管周围干酪样病变、炎性细胞和碎屑、纤维化和肉芽肿形成的混合物。结论结核性“树芽征”代表肺结核支气管腔内播散过程中的特殊病理过程,在临床工作中可以为肺结核诊治提供证据。

关键词：结核,肺树芽征病理

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A Curved Four-Conductor Assembly with Larger Uniform Region

A Curved Four-Conductor Assembly with Larger Uniform Region

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2023 Joint Conference of the European Frequency and Time Forum and IEEE International Frequency Control Symposium, EFTF/IFCS 2023

作者： li, Chao Hu, xuwen Sun, Fuyu liu, Jie li, Xiaofeng Zhang, Shougang National Time Service Center Chinese Academy of Sciences Xi'an China University of Chinese Academy of Sciences Beijing China

ISBN: (纸本)9798350311426

Most atomic physics setups require a uniform static magnetic field to define a quantization axis. The straight four-conductor assembly has been proven to be a useful structure for producing such a uniform static magnetic field. Here, we present an improved four-conductor assembly, where each conductor consists of one straight section and two curved sections. This hybrid structure arrangement offers more degrees of freedom than the conventional straight four-conductor assembly, enabling a larger uniform field region and better field spatial uniformity. The modified magnetic field generation structure can be used in many fields of atomic precision spectroscopy. © 2023 IEEE.

关键词： curved section four-conductor modified four-conductor static magnetic field uniformity

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Association between hypertension and prognosis of patients with COVID-19: A systematic review and meta-analysis

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CliNICAL AND EXPERIMENTAL HYPERTENSION 2022年第5期44卷 451-458页

作者： Qian, Zhe li, Zhuohong Peng, Jie Gao, Qiqing Cai, Shaohang Xu, xuwen Southern Med Univ Nanfang Hosp Dept Infect Dis 1838 Guangzhou Ave North Guangdong Kguangzhou GD Peoples R China

Background To investigate the association between hypertension and clinical outcomes, including in-hospital mortality, intensive care unit (ICU) admission, and invasive ventilation in patients with coronavirus disease 2019 (COVID-19) pneumonia. Methods We implemented a systematic search of PubMed for articles that assessed clinical outcomes of hypertensive patients infected with SARS-CoV-2. The primary outcomes evaluated included: in-hospital mortality, ICU admission, and the use of invasive ventilation. Results A total of 18 studies were included, involving 13,293 patients and covering from January 25, 2020, to April 20, 2020. The relationship between hypertension and prognosis in COVID-19 patients was evaluated. Results showed that hypertension was a risk factor for in-hospital mortality in COVID-19 patients (RR: 2.20, 95% CI, 1.83-2.65, P < .001). Moreover, patients with hypertension were more likely to be admitted to ICU (RR: 1.86, 95% CI, 1.13-3.07, P = .001) and to use invasive ventilation (RR: 2.99, 95% CI, 1.73-5.17, P < .001). Conclusions Among COVID-19 patients, those combined with hypertension had a significantly higher risk of in-hospital deaths, admission to ICU, and need for invasive ventilation.

关键词： COVID-19 epidemiology hypertension respiratory infections virology

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A Two-level Learning Approach for Achieving the Sustainable Development of Service Ecosystem

A Two-level Learning Approach for Achieving the Sustainable ...

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IEEE International Conference on Web Services (IEEE ICWS)

作者： Peng, Chao Xue, Xiao Zhang, xuwen Ji, Peilin Shen, Yifan Fang, li Feng, Zhiyong Tianjin Univ Coll Intelligence & Comp Tianjin Peoples R China Tianjin Key Lab Healthy Habitat & Mart Technol Tianjin Peoples R China Xian Univ Finance & Econ Sch Informat Xian Peoples R China

ISBN: (纸本)9798350368567;9798350368550

The governance of service ecosystem needs to balance efficiency and fairness to promote the sustainable development of the system, making it an important topic. However, service entities in the service ecosystem have autonomy and engage in dynamic game with governance strategies, leading to governance challenges. To address this issue, we model the governance process as a repeated sequential game between the governance algorithm and service entities, and propose a novel two-level learning algorithm. This algorithm considers the learning evolution of service entities and the co-evolutionary of the governance algorithm, using reinforcement learning to learn effective governance strategies while also considering the response function of service entities to balance efficiency and fairness. Combining the ideas of bilevel optimization and online learning, this algorithm effectively balances exploration (understanding the service entities' responses function) and exploitation (choosing efficient actions). We apply the algorithm to a classic service ecosystem, the ride-hailing service system, and empirically demonstrate its effectiveness in the governance task of order dispatching.

关键词： Service Ecosystem Governance Reinforcement Learning Balancing Efficiency and Fairness

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自体髂骨块植骨结合Calcar螺钉重建内侧柱治疗复杂肱骨近端骨折

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中华肩肘外科电子杂志 2021年第3期9卷 244-248页

作者：祝相如张聿达李绪文刘国明梁承志扈延龄青岛大学医学部 266073 青岛大学附属医院创伤外科 266000

目的探讨自体髂骨块移植结合Calcar螺钉重建内侧柱治疗肱骨近端骨折的临床疗效。方法回顾性分析我院自2016年1月至2018年12月收治的36例单侧复杂肱骨近端骨折患者,采用自体髂骨块移植结合Calcar螺钉治疗。随访时间12~24个月,平均17.04... 详细信息

目的探讨自体髂骨块移植结合Calcar螺钉重建内侧柱治疗肱骨近端骨折的临床疗效。方法回顾性分析我院自2016年1月至2018年12月收治的36例单侧复杂肱骨近端骨折患者,采用自体髂骨块移植结合Calcar螺钉治疗。随访时间12~24个月,平均17.04个月。记录术后3、6、12个月随访时Neer肩关节功能评分(Neer评分)和肩关节功能评分(Constant评分);采用视觉模拟评分(visual analogue scale,VAS)评估患者术后疼痛程度。分析患者骨折愈合时间、并发症发生情况及肩关节活动范围。结果36例患者均达到解剖复位,骨折平均愈合时间为3.71个月,没有患者出现肱骨头缺血性坏死及内翻塌陷。术后12个月随访时,患者Neer评分(84.64±3.40)分;Constant评分(74.26±4.70)分;VAS(1.24±0.72)分。患肩关节活动度:屈(132.58±8.01)°、伸(43.75±3.41)°、内旋(58.25±4.89)°、体侧外旋(58.89±4.83)°、外展(136.46±11.04)°。结论对于内侧粉碎性复杂肱骨近端骨折,自体髂骨块植骨结合Calcar螺钉能够重建可靠的内侧支撑,降低内翻塌陷及肱骨头缺血性坏死等并发症的风险,术后功能恢复满意。

关键词：肱骨近端骨折髂骨植骨内侧柱骨移植

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