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Constant-round auction with insulated bidders

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Science China(Information Sciences) 2022年第4期65卷 264-266页

作者： jie MA Bin qi Kewei LV State Key Laboratory of Information Security Institute of Information EngineeringChinese Academy of Sciences Data Assurance and Communication Security Research Center Chinese Academy of Sciences School of Cyber Security University of Chinese Academy of Sciences

Dear editor,In recent years, online auction has gained widespread popularity as a primary characteristic of electronic commerce among masses. It has also become a primary topic of research interest. Cryptographic primitives such as secure multiparty computation(MPC) [1], zero-knowledge proof(ZKP) [2] and commitment scheme [3] are being effectively utilized for the proposal of various schemes. Therefore,

关键词： Auction Commitment Integer Comparison Protocol Constant-round Blockchain

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Numerical Simulation and Experimental Studies on Elastic-Plastic Fatigue Crack Growth

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Computer Modeling in Engineering & Sciences 2019年第2期118卷 377-395页

作者： jie Wang Wei Jiang qi Wang School of Mechanical Engineering Dalian University of TechnologyDalian116024China.

A elastic-plastic fatigue crack growth(FCG)finite element model was developed for predicting crack growth rate under cyclic *** propagation criterion for this model was established based on plastically dissipated *** crack growth simulation under cyclic computation was implemented through the ABAQUS scripting *** predictions of this model are in good agreement with the results of crack propagation experiment of compact tension specimen made of 304 stainless *** on the proposed model,the single peak overload retardation effect of elastic-plastic fatigue crack was *** results shows that the single peak overload will reduce the accumulation rate of plastic energy dissipation of elements at crack tip plastic zone,so that crack growth will be *** crack growth rate will not recover until the crack tip exceed the affected ***,the crack growth rate is mainly determined by the amplitude rather than the mean load under the condition of small scale *** proposed model would be helpful for predicting the growth rate of mode I elastic-plastic fatigue crack.

关键词： Plastic dissipation energy elastic-plastic fatigue crack finite element model crack growth rate.

A TIME DOMAIN BLIND DECORRELATION METHOD OF CONVOLUTIVE MIXTURES BASED ON AN IIR MODEL

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Journal of Computational Mathematics 2010年第3期28卷 371-385页

作者： jie Liu Jack Xin Yingyong qi Department of Mathematics National University of Singapore Singapore Department of Mathematics University of California Irvine USA Department of Mathematics University of California Irvine USAand School of Information Engineering Shangdong University at Weihai China

We study a time domain decorrelation method of source signal separation from convolutive sound mixtures based on an infinite impulse response （IIR） model. The IIR model uses fewer parameters to capture the physical mixing process and is useful for finding low dimensional separating solutions. We present inversion formulas to decorrelate the mixture signals and derive filter equations involving second order time lagged statistics of mixtures. We then formulate an 11 constrained minimization problem and solve it by an iterative method. Numerical experiments on recorded sound mixtures show that our method is capable of sound separation in low dimensional parameter spaces with good perceptual quality and low correlation coefficient comparable to the known infomax method.

关键词： Blind Decorrelation Convolutive Mixtures IIR Modeling l1 ConstrainedMinimization

Numerical study on three-dimensional CJ detonation waves interacting with isotropic turbulence

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Science Bulletin 2016年第22期61卷 1756-1765页

作者： Tai Jin Kun luo qi Dai Jianren Fan State Key Laboratory of Clean Energy Utilization Zhejiang University

The three-dimensional structures of a cellular detonation wave interacting with different turbulent flows were investigated using a one-step irreversible Arrhenius kinetics model. High-resolution bandwidth-optimized WENO scheme of spatial discretization and total variation diminishing temporal integration are used to solve the three dimensional chemically reactive Navier-Stokes equations. The turbulent vertical and entropic forcing effects on the three dimensional detonation wave structures and dynam- ics are analyzed, as well as the detonation effects on tur- bulent vortex structures. It has been found that the turbulence field imposed has created small scale wrinkles embedded in the detonation front, apart from the large scale features of detonation without turbulence. The deto- nation propagating velocity over the leading shock front varies from 0.8 to 1.6 times of CJ velocity and its proba- bility density function （pdf） skews towards sub-CJ velocity and peaks at about 0.9. The recorded detonation velocity always preferentially decays with time, with very rapid accelerations through triple point interactions. Its pdf also skews to sub-CJ velocity, while its overall shape agrees well with W3. The reaction zone is greatly influenced by the vortex, much more irregular and elongated for the turbulent cases. Distributed burning pockets are more likely to be found there. The turbulent kinetic energy is amplified across the detonation, and periodically oscillates downstream the detonation. The off-diagonal components of Reynolds stress also show a rapid rise across the deto- nation and present to be non-zero downstream of detona- tion. Vortex structures are compound results of the convected vortex and the generated vortex by the collision of triple points. The convection term and baroclinic gen- eration term in the transport equation of enstrophy are compared in detail.

关键词： Direct numerical simulation CJ detonation Turbulence Detonation structure

Prevalence of coronary artery ectasia in older adults and the relationship with epicardial fat volume by cardiac computed tomography angiography

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Journal of Geriatric Cardiology 2013年第1期10卷 10-15页

作者： Jun-jie Yang Xia Yang Zhi-Ye Chen qi Wang Bai He luo-Shan Du Yun-Dai Chen Department of Cardiology Chinese PLA General Hospital 28 Fuxing Road Beijing 100853 China Department of Radiology Chinese PLA General Hospital 28 Fuxing Road Beijing 100853 China

Objective Coronary artery ectasia (CAE) refers to abnormal dilation of coronary artery segments to 1.5 times of adjacent normal ones. Epicardial fat is associated with cardiovascular risk factors. The relationship between CAE and epicardial fat has not yet been investigated. This study aimed to assess the relationship between CAE and epicardial fat volume (EFV) in older people by dual-source computed tomography coronary angiography (CTCA). Methods We prospectively enrolled 1400 older adults who were scheduled for dual-source CTCA. Under reconstruction protocols, patients with abnormal segments 1.5 times larger than the adjacent segments were accepted as CAE. EFV was measured by semi-automated software. Traditional risk factors in CAE patients, as well as the extent of EFV, were analyzed and compared to non-CAE group. Results A total of 885 male and 515 female older patients were enrolled. CAE was identified by univariable analysis in 131 patients and significantly correlated to hypertension, smoking, hyperlipidemia, prior percutaneous coronary intervention and ascending aorta aneurysm. EFV was shown to be significantly higher inCAE patients than patients without ectasia. Inmultivariable analyses, EFV (P = 0.018), hypertension (P < 0.001) and hyperlipidemia (P < 0.001) were significantly correlated to CAE. There was a significant negative correlation between EFV and Markis classification. Conclusions CAE can be reliably recognized by dual-source CTCA. Epicardial fatmight play a role in etiopathogenesis and progression of CAE, providing a newtarget for treating ectasia.

关键词： Cardiac computed tomography angiography Coronary artery ectasia Epicardial fat

Extending the detection limit:innovations in infrared quantum dot photodetectors reaching up to 18μm

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Light(Science & Applications) 2024年第8期13卷 1445-1447页

作者： Chong Wu Wang qi jie Wang Centre for OptoElectronics and Biophotonics School of Electrical and Electronic EngineeringNanyang Technological UniversitySingapore 639798Singapore Centre for Disruptive Photonic Technologies School of Physical and Mathematical SciencesNanyang Technological UniversitySingaporeSingapore

A regrowth method was used to synthesize large-sized colloidal quantum dots(CQDs).With the assistance of doping engineering,the synthesized CQD detectors demonstrate exceptional long-wavelength infrared detection performance,reaching up to 18μm,significantly extending the spectral response limit for CQD-based infrared *** detectors also achieve a reasonably high detectivity of 6.6×10^(8)Jones.

关键词： limit quantum sized

Tight sandstone gas accumulation mechanism and development models

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Petroleum Science 2015年第4期12卷 587-605页

作者： Zhen-Xue Jiang Zhuo Li Feng Li Xiong-qi Pang Wei Yang luo-Fu Liu Fu-jie Jiang State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum Unconventional Natural Gas Institute China University of Petroleum College of Geosciences China University of Petroleum

Tight sandstone gas serves as an important unconventional hydrocarbon resource, and outstanding results have been obtained through its discovery both in China and abroad given its great resource potential. However, heated debates and gaps still remain regarding classification standards of tight sandstone gas, and critical controlling factors, accumulation mechanisms, and devel- opment modes of tight sandstone reservoirs are not deter- mined. Tight sandstone gas reservoirs in China are generally characterized by tight strata, widespread distri- bution areas, coal strata supplying gas, complex gas-water relations, and abnormally low gas reservoir pressure. Water and gas reversal patterns have been detected via glass tube and quartz sand modeling, and the presence of critical geological conditions without buoyancy-driven mecha- nisms can thus be assumed. According to the timing of gas charging and reservoir tightening phases, the following three tight sandstone gas reservoir types have been identified：（a）＂accumulation-densification＂（AD）, or the conventional tight type, （b）＂densification-accumulation＂（DA）, or the deep tight type, and （c） the composite tight type. For the AD type, gas charging occurs prior to reser- voir densification, accumulating in higher positions under buoyancy-controlled mechanisms with critical controlling factors such as source kitchens （S）, regional overlaying cap rocks （C）, gas reservoirs, （D） and low fluid potential areas （P）. For the DA type, reservoir densification prior to the gas charging period （GCP） leads to accumulation in depres- sions and slopes largely due to hydrocarbon expansive forces without buoyancy, and critical controlling factors are effective source rocks （S）, widely distributed reservoirs （D）, stable tectonic settings （W） and universal densification of reservoirs （L）. The composite type includes features of the AD type and DA type, and before and after reservoir densification period （RDP）, gas charging and accumulation

关键词： Tight sandstone gas Reservoir features Accumulation mechanism Type classification Development mode

Point Defect Engineering Boosting the Thermoelectric Properties of Layered 122 Zintl Compounds

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Chinese Journal of Structural Chemistry 2020年第5期39卷 815-820页

作者： GUO Kai HUO Hao-jie luo Jun School of Materials Science and Engineering Shanghai UniversityShanghai 200444China Materials Genome Institute Shanghai UniversityShanghai 200444China

The layered 122 Zintl compounds have become an intriguing class of thermoelectric materials due to the promising electronic transport properties and inherently low thermal conductivity,showing the typical characteristics of"phonon-glass electron-crystal".Owing to the unprecedented performance tunability,the thermoelectric properties of the layered-structure compounds are completive with some traditional thermoelectric *** defects involving vacancy,aliovalent doping and equivalent alloying atoms have been introduced to further enhance the thermoelectric *** review emphasizes the effects of various point defects on the thermoelectric parameters,and provides perspective on the strategies for increasing the thermoelectric figure of merit zT,which are believed to be applicable for improving the thermoelectric properties of many other compounds.

关键词： layered structure 122 Zintl phase point defect orbital alignment phonon scattering thermoelectric properties

Multi-party privacy-preserving decision tree training with a privileged party

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Science China(Information Sciences) 2024年第8期67卷 253-268页

作者： Yiwen TONG qi FENG Min luo Debiao HE Key Laboratory of Aerospace Information Security and Trusted Computing Ministry of Education School of Cyber Science and Engineering Wuhan University Shanghai Technology Innovation Centre of Distributed Privacy-Preserving Artificial Intelligence Matrix Elements Technologies Key Laboratory of Computing Power Network and Information Security Ministry of EducationShandong Computer Science Center Qilu University of Technology(Shandong Academy of Sciences)

Currently, a decision tree is the most commonly used data mining algorithm for classification tasks. While a significant number of studies have investigated privacy-preserving decision trees, the methods proposed in these studies often have shortcomings in terms of data privacy breach or efficiency. Additionally,these methods typically only apply to symmetric frameworks, which consist of two or more parties with equal privilege, and are not suitable for asymmetric scenarios where parties have unequal privilege. In this paper,we propose SecureCART, a three-party privacy-preserving decision tree training scheme with a privileged party. We adopt the existing pMPL framework and design novel secure interactive protocols for division,comparison, and asymmetric multiplication. Compared to similar schemes, our division protocol is 93.5–560.4× faster, with the communication overhead reduced by over 90%; further, our multiplication protocol is approximately 1.5× faster, with the communication overhead reduced by around 20%. Our comparison protocol based on function secret sharing maintains good performance when adapted to pMPL. Based on the proposed secure protocols, we implement SecureCART in C++ and analyze its performance using three real-world datasets in both LAN and WAN environments. he experimental results indicate that SecureCART is significantly faster than similar schemes proposed in past studies, and that the loss of accuracy while using SecureCART remains within an acceptable range.

关键词： privacy protection decision trees secure multi-party computation secret sharing privileged party