Search

Your search keyword '"Li, Wenting"' showing total 2,829 results
Start Over Author "Li, Wenting"
2,829 results on '"Li, Wenting"'

110. EVMPatch: Timely and Automated Patching of Ethereum Smart Contracts

Author

Rodler, Michael, Li, Wenting, Karame, Ghassan O., and Davi, Lucas

Subjects
Computer Science - Cryptography and Security, Computer Science - Distributed, Parallel, and Cluster Computing
Abstract

Recent attacks exploiting errors in smart contract code had devastating consequences thereby questioning the benefits of this technology. It is currently highly challenging to fix errors and deploy a patched contract in time. Instant patching is especially important since smart contracts are always online due to the distributed nature of blockchain systems. They also manage considerable amounts of assets, which are at risk and often beyond recovery after an attack. Existing solutions to upgrade smart contracts depend on manual and error-prone processes. This paper presents a framework, called EVMPatch, to instantly and automatically patch faulty smart contracts. EVMPatch features a bytecode rewriting engine for the popular Ethereum blockchain, and transparently/automatically rewrites common off-the-shelf contracts to upgradable contracts. The proof-of-concept implementation of EVMPatch automatically hardens smart contracts that are vulnerable to integer over/underflows and access control errors, but can be easily extended to cover more bug classes. Our extensive evaluation on 14,000 real-world (vulnerable) contracts demonstrate that our approach successfully blocks attack transactions launched on these contracts, while keeping the intended functionality of the contract intact. We perform a study with experienced software developers, showing that EVMPatch is practical, and reduces the time for converting a given Solidity smart contract to an upgradable contract by 97.6 %, while ensuring functional equivalence to the original contract., Comment: A slightly shorter version of this paper will be published at USENIX Security Symposium 2021

Published
2020

111. Physics-Informed Learning for High Impedance Faults Detection

Author

Li, Wenting and Deka, Deepjyoti

Subjects
Electrical Engineering and Systems Science - Signal Processing, Electrical Engineering and Systems Science - Systems and Control
Abstract

High impedance faults (HIFs) in distribution grids may cause wildfires and threaten human lives. Conventional protection relays at substations fail to detect more than 10\% HIFs since over-currents are low and the signatures of HIFs are local. With more $\mu$PMU being installed in the distribution system, high-resolution $\mu$PMU datasets provide the opportunity of detecting HIFs from multiple points. Still, the main obstacle in applying the $\mu$PMU datasets is the lack of labels. To address this issue, we construct a physics-informed convolutional auto-encoder (PICAE) to detect HIFs without labeled HIFs for training. The significance of our PICAE is a physical regularization, derived from the elliptical trajectory of voltages-current characteristics, to distinguish HIFs from other abnormal events even in highly noisy situations. We formulate a system-wide detection framework that merges multiple nodes' local detection results to improve the detection accuracy and reliability. The proposed approaches are validated in the IEEE 34-node test feeder simulated through PSCAD/EMTDC. Our PICAE outperforms the existing works in various scenarios and is robust to different observability and noise., Comment: 7 pages, 6 figures

Published
2020

118. FINTECHS AND SME SUPPLIERS: LIQUIDITY THROUGH DIGITIZATION

Author

Li, Wenting, Choi, Thomas Y., and Rogers, Dale S.

Subjects
High technology industry, Small and medium sized companies, Logistics, Digitization, Business, general, Business
Abstract

Credit barriers and extended payment terms hamper the operational ability of tier 2 and tier 3 supply chain participants. But a new breed of technology companies are here to help. [...]

Published
2023

124. Safety and antitumour activity of cadonilimab, an anti-PD-1/CTLA-4 bispecific antibody, for patients with advanced solid tumours (COMPASSION-03): a multicentre, open-label, phase 1b/2 trial

Author

Gao, Xiangyu, Xu, Nong, Li, Ziyu, Shen, Lin, Ji, Ke, Zheng, Zhong, Liu, Dan, Lou, Hanmei, Bai, Li, Liu, Tianshu, Li, Yunxia, Li, Yuzhi, Fan, Qingxia, Feng, Mei, Zhong, Haijun, Huang, Yi, Lou, Ge, Wang, Jing, Lin, Xiaoyan, Chen, Ye, An, Ruifang, Li, Changzheng, Zhou, Qi, Huang, Xin, Guo, Zengqing, Wang, Shubin, Li, Guiling, Fei, Junwei, Zhu, Lijing, Zhu, Hong, Li, Xiumin, Li, Fenghu, Liao, Sihai, Min, Qinghua, Tang, Lei, Shan, Fei, Gong, Jifang, Gao, Yunong, Zhou, Jun, Lu, Zhihao, Li, Xiaofan, Li, Jianjie, Ren, Hui, Liu, Xiaohong, Yang, Hongxia, Li, Wenting, Song, Weifeng, Wang, Zhongmin Maxwell, Li, Baiyong, Xia, Michelle, Wu, Xiaohua, and Ji, Jiafu

Published
2023
Full Text
View/download PDF

131. AK112, a novel PD-1/VEGF bispecific antibody, in combination with chemotherapy in patients with advanced non-small cell lung cancer (NSCLC): an open-label, multicenter, phase II trial

Author

Zhao, Yuanyuan, Chen, Gang, Chen, Jianhua, Zhuang, Li, Du, Yingying, Yu, Qitao, Zhuang, Wu, Zhao, Yanqiu, Zhou, Ming, Zhang, Weidong, Zhang, Yu, Wan, Yixin, Li, Wenting, Song, Weifeng, Wang, Zhongmin Maxwell, Li, Baiyong, Xia, Michelle, Yang, Yunpeng, Fang, Wenfeng, Huang, Yan, and Zhang, Li

Published
2023
Full Text
View/download PDF

132. In-Vitro and In-Silico Assessment of Per- and Polyfluoroalkyl Substances (PFAS) in Aqueous Film-Forming Foam (AFFF) Binding to Human Serum Albumin

Author

Li, Wenting, Hu, Yuhong, and Bischel, Heather N

Subjects
Analytical Chemistry, Chemical Sciences, PFAS, equilibrium dialysis, bioconcentration, suspect screening, docking
Abstract

Drinking water contaminated by fluorosurfactant-based aqueous film-forming foams (AFFF) is a source of human exposure to poly- and perfluoroalkyl substances (PFAS). However, assessment of bioaccumulation potentials of diverse PFAS in commercial products such as AFFF have been insufficient and challenging, especially due to a lack of analytical standards. Here we explore the value of suspect screening, equilibrium dialysis, and molecular-docking simulations to identify potentially bioaccumulative PFAS. We exposed human serum albumin (HSA) protein to dilutions of a legacy AFFF produced by 3M in 1999 using equilibrium dialysis and screened in-vitro protein-binding affinities using high-resolution mass spectrometry (HRMS). Through suspect screening, we identified 32 PFAS and 18 hydrocarbon surfactants in the AFFF that bound to HSA. Quantification of noncovalent association constants for 26 PFAS standards confirmed that many PFAS, including the short-chain perfluoropropane sulfonic acid (log Ka= 4.1 ± 0.2 M-1), exhibit strong binding affinities with HSA. At least five PFAS in AFFF (including three PFAS with less than five perfluorocarbons) remained bound to the precipitated HSA pellet after extensive solvent washing-an indication of high PFAS binding potential. Three PFAS (PFBS, PFOS, and PFOA) were confirmed in the protein pellet with analytical standards and quantified after acid digestion-this sample fraction accounted for 5 to 20% of each compound mass in the sample. We calculated pseudo-bioconcentration factors (BCFpseudo) for PFAS that suspect screening flagged as noncovalently bound or potentially covalently bound. Most PFAS exhibiting high BCFpseudo, especially those with seven perfluorocarbons, contained a carboxylic acid or a sulfonic acid. Finally, we used molecular docking to simulate HSA binding affinities for 62 ligands (26 PFAS targets, 18 PFAS qualified in AFFF, and 18 hydrocarbon surfactants qualified in AFFF). We found that molecular docking can effectively separate HSA-binding and -nonbinding compounds in AFFF. In-vitro and in-silico approaches described in this study provide replicable, high-throughput workflows for assessing bioaccumulation potentials of diverse PFAS in commercial products.

Published
2021

139. Growth performance, nutrient digestibility, and fecal microbial composition of weaned pigs fed multi-enzyme supplemented diets.

Author

Park, Sangwoo, Li, Wenting, St-Pierre, Benoit, Wang, Qiong, and Woyengo, Tofuko Awori

Subjects
Agricultural, Veterinary and Food Sciences, Animal Production, Biological Sciences, Clinical Research, Nutrition, Clinical Trials and Supportive Activities, 6-Phytase, Animal Feed, Animals, Diet, Dietary Supplements, Digestion, Feces, Female, Gastrointestinal Tract, Male, Nutrients, Peptide Hydrolases, Swine, Weaning, Zea mays, fecal microbial composition, growth performance, multi-enzyme, nutrient digestibility, weaned pigs, Agricultural and Veterinary Sciences, Dairy & Animal Science, Agricultural, veterinary and food sciences, Biological sciences
Abstract

A study determined the effects of supplementing corn-based diets for weaned pigs with multi-enzymes on growth performance, apparent total tract digestibility (ATTD) of nutrients, fecal score, and fecal microbial composition. A total of 132 pigs (initial body weight = 7.23 kg) that had been weaned at 21 d of age and fed a drug-free nursery diet for 7 d were housed in 33 pens of 4 barrows or gilts, blocked by body weight and gender, and fed 3 experimental diets at 11 pens per diet. The diets were corn-based diet without or with multi-enzyme A or B. Multi-enzyme A supplied 4,000 U of xylanase, 150 U of β-glucanase, 3,500 U of protease, and 1,500 U of amylase per kilogram of diet. Multi-enzyme B was the same as multi-enzyme A except that it supplied amylase at 150 U/kg, and that its source of amylase was different from that of multi-enzyme A. All diets contained phytase at 1,000 U/kg. The diets were fed for 35 d in 2 phases; phase 1 for the first 14 d and phase 2 for the last 21 d of the trial. Fecal score was determined daily during the first 7 d of the trial. Fecal samples were collected from rectum of 1 pig per pen on days 2, 7, 14, and 35 of the trial for determining bacterial composition. Also, fresh fecal samples were collected from each pen on days 41 and 42 to determine ATTD of nutrients. Multi-enzyme B increased (P < 0.05) average daily gain (ADG) for phases 1 and 2. For the overall study period, multi-enzyme B increased (P < 0.05) ADG from 262 to 313 g, and average daily feed intake (ADFI) from 419 to 504 g. Multi-enzyme A increased (P < 0.05) overall ADG from 262 to 290 g, but did not affect ADFI. Multi-enzyme A or B did not affect ATTD of gross energy, but increased (P < 0.05) the ATTD of ether extract from 30% to 36% or 37%, respectively. Multi-enzyme A did not affect fecal score; however, multi-enzyme B tended to decrease (P = 0.09) fecal score, implying that it tended to decrease diarrhea. Firmicutes were the most abundant phylum of fecal bacteria (its relative abundance ranged from 58% to 72%). Bacteroidetes and Actinobacteria were the 2nd and 3rd most abundant phyla of fecal bacteria. Neither multi-enzyme affected fecal bacterial composition. In conclusion, the addition of multi-enzyme A or B to phytase-supplemented corn-based diet for weaned pigs can improve their growth performance and fat digestibility. However, multi-enzyme B was more effective than multi-enzyme A in terms of improving the growth performance of weaned pigs fed corn-based diet.

Published
2020

140. Sereum: Protecting Existing Smart Contracts Against Re-Entrancy Attacks

Author

Rodler, Michael, Li, Wenting, Karame, Ghassan O., and Davi, Lucas

Subjects
Computer Science - Cryptography and Security
Abstract

Recently, a number of existing blockchain systems have witnessed major bugs and vulnerabilities within smart contracts. Although the literature features a number of proposals for securing smart contracts, these proposals mostly focus on proving the correctness or absence of a certain type of vulnerability within a contract, but cannot protect deployed (legacy) contracts from being exploited. In this paper, we address this problem in the context of re-entrancy exploits and propose a novel smart contract security technology, dubbed Sereum (Secure Ethereum), which protects existing, deployed contracts against re-entrancy attacks in a backwards compatible way based on run-time monitoring and validation. Sereum does neither require any modification nor any semantic knowledge of existing contracts. By means of implementation and evaluation using the Ethereum blockchain, we show that Sereum covers the actual execution flow of a smart contract to accurately detect and prevent attacks with a false positive rate as small as 0.06% and with negligible run-time overhead. As a by-product, we develop three advanced re-entrancy attacks to demonstrate the limitations of existing offline vulnerability analysis tools.

Published
2018

Catalog

Books, media, physical & digital resources
See catalog results