基于环上误差学习问题的新型后量子认证密钥交换协议

针对量子计算机技术的迅速发展使得传统公钥密码体制的安全性面临严重威胁的现实性问题,提出一种新型的基于环上误差学习（RLWE）问题的后量子认证密钥交换协议。协议通过使用Peikert式误差协调机制,双方通过计算可直接得到均匀分布的共享比特值,从而使得通信双方得到相同的会话密钥。使用理想格上的解码基对协议正确性进行了分析,并设置合理参数从而保证协议双方以显著概率得到相同密钥值。该协议在BR （Bellare-Rogaway）模型下可证明安全并达到弱的完美前向安全性。协议安全性归约为格上RLWE困难问题,可抵御量子攻击。与现有基于RLWE问题设计的认证密钥交换协议相比,该协议中参数值模数的大小由亚指数级降低至多项式级,相应计算量和通信量显著减小,是一种更加简洁高效的后量子认证密钥交换协议。     

Diagnostic test decision for suppliers in cruise-building supply chain with information asymmetry

To solve the potential supply disruption in cruise-building supply chain, this study explores a supply system consisting of a monopoly supplier, a new entrant supplier, and a cruise-building manufacturer. A two-step option contract including diagnostic test and process improvement is designed to solve the order quantity allocation and to avoid supply disruption. The analysis combines the decision tree with the principal-agent model under information asymmetry. The result shows that the cruise-building manufacturer would like to allocate more orders to the unreliable supplier who implements process improvement. In the end, the detailed numerical analysis is implemented to justify the proposal.     

轴承试验中心分布式监控管理系统

本文设计了轴承试验中心分布式监控管理系统，系统可对多台试验机进行在线监测，对被试验轴承做实时诊断，有故障时立即报警，并可将整个试验过程数据通过网络传送到上位机进行显示并存储到数据库中，供技术人员分析使用。该系统已在轴承生产企业得到了成功的应用。     

A critical appraisal of javelin high speed cinematography results using a computer flight simulation program

Abstract

Errors in javelin release parameters obtained from high-speed film analysis of real throws have been quantified in order to assess the accuracy of studies that assume a rigid body javelin model when measuring human performance characteristics. Human digitizing errors and the inadequate rigid body javelin model represent increments of up to 6 m in range as predicted by a computer flight simulation program. These errors result from difficulties in digitizing blurred javelin coordinates caused by large release speeds and javelin flutter. Errors in release-pitch rate are as high as 27·0%. Digital filtering methods tend to underestimate transiational and angular speeds such that errors in previous literature represent simulated range increments of up to 29 m. This is owing to the filtering methods interpreting high frequency flutter as noise. It is concluded that present methods in javelin film analysis are inadequate for measuring absolute values of release parameters and need to be revised. Accurate quantification is essential before simulation programs can be used in a human performance perspective.     

优化的基于错误学习问题的CKKS方案

针对基于错误学习(LWE)问题的CKKS同态加密方案在密态数据计算中存在的密文大、计算密钥生成复杂以及同态计算效率低的缺陷,运用比特丢弃和同态计算密钥重组的方法,提出了一种优化的LWE型CKKS方案.首先,丢弃密文向量的部分低位比特和同态乘法计算中密文张量积的部分低位比特,从而减小了同态乘法过程中的密文规模;其次,针对...     

Can self-estimates of body weight and height be used in place of measurements for college students?

A study was conducted to determine how accurately college students can estimate their height and body weight. Four hundred and sixty-nine students (136 females and 333 males) completed a short questionnaire eliciting self-estimates of height and weight, frequency and recency of measuring them, age, and gender. Immediately afterwards, their height and weight were measured. Three hundred and forty-nine subjects were told that they would be measured later; the others were not told that they would be measured. Analysis of the data revealed relatively small absolute errors of estimation (1.00—3.54%); both males and females overestimated height and underestimated weight; females estimated weight less accurately and height more accurately than males; and knowing that one's estimation would be checked by measurement produced slightly more accurate estimations. Simple self-estimates of height and weight are accurate enough to be used in place of measurements.     

VB程序的调试与错误处理

文章介绍了VB程序的常见错误、错误类型、常用的调试方法以及错误处理程序。对于提高VB应用程序的开发效率非常有用。     

电压频率转换器在诊断X射线检测中的应用

根据诊断X射线检测的设计要求,结合STM32单片机的特点,将电压频率转换器应用到诊断X射线检测系统中。分析了电压频率转换器的工作原理,给出了电压频率转换器电路设计及诊断X射线检测系统的硬件构成,并对检测系统的控制程序流程进行详细的说明。电压频率转换器具有设计简单、低成本、高精度、应用灵活等特点,适合于低速数据采集。     

Suboptimal robust synthesis for MIMO plant under coprime factor perturbations

Suboptimal robust synthesis for MIMO nominal system under coprime factor perturbations is considered in classical and non-classical statements. In the classical statement, weights of perturbations and upper bound on magnitude bounded exogenous disturbance are assumed to be known to controller designer. Suboptimal synthesis within ε tolerance is reduced to the solution of log₂(1/ε) standard mixed sensitivity problems of ℓ₁ optimization. In the non-classical statement, the upper bounds on perturbations and exogenous disturbance are to be estimated from measurement data and suboptimal synthesis is reduced to the solution of 1/ε mixed sensitivity problems.