基于IP和GEP算法的股票预测

采用免疫算法和基于基因表达式编程的混合算法建立了股票指数预测模型。实验结果显示,该模型能够以相当高的精度预测股票指数。     

基于COM的MATLAB与Delphi混合编程研究*

MATLAB是功能非常强大的科学工具软件,Delphi是Windows平台下功能齐全的快速开发工具,组件对象模型(COM)为Windows提供了统一的、面向对象的、可扩充的通信协议。论述了采用MATLAB的COM Builder开发COM组件及在Delphi下接口、调用的方法。     

基于Win32 API的未知病毒检测

提出了一个基于行为特征向量的病毒检测方法。特征向量的每一维用于表示一种恶意行为事件,每一事件由相应的Win32应用程序编程接口(API)调用及其参数表示,并实现了一个自动化行为追踪系统(Argus)用于行为特征的提取。试验中,通过对样本数据的分析,利用互信息对特征向量进行属性约简,减少特征维数。试验结果表明,约简后的模型对于发生行为事件数大于1的病毒程序仍有着较好的检测效果。     

基于H.264帧内预测宏块融合置乱技术的安全通信研究

基于I、P、B帧中所有帧内预测宏块与整数离散余弦变换DCT(Discrete Cosine Transform)提出了一种融合加密方案。判断当前宏块的属性是帧内预测宏块,则将其DCT系数分层即宏块系数矩阵做转置变换,获得16个新的4×4子宏块,用混沌系统产生的密钥序列置乱子宏块后再加密子宏块中的系数符号。实验结果表明,这种融合加密方案不仅能有效防止块间相关性攻击和密钥攻击,同时也能满足视频的安全性和传输的实时性要求。     

Variational inequality in classical plasticity. Applications to Armstrong–Frederick elasto-plastic model

In this paper the quasi-static initial and boundary value problem for an elasto-plastic mixed hardening material is reformulated within the constitutive framework of small strains. The plastic factor plays the basic role in describing the rate independent evolution equations for the plastic strain and hardening variables. The plastic factor is equivalently represented as the solution of an appropriate local inequality involving the yield function. The main idea was to introduce the variational inequality at any time $t$ to be solved for the velocity field and the complementary plastic factor. There is the plastic factor in a strain-driven process. The solution procedure proposed here to solve the initial and boundary value problem is based on the solutions of the variational inequality at time $t$, coupled with an update algorithm in order to evaluate the current state of the material for an incremental deformation process. This time the return mapping algorithm is avoided as the values of the plastic factor and the velocity are known at time $t.$ As we developed a procedure to simultaneously solve the equilibrium equation coupled with the rate-independent evolution equations, no necessity to compute the algorithmic elasto-plastic tangent moduli occurs. The numerical simulations are done for the mixed hardening elasto-plastic model involving Armstrong–Frederick kinematic hardening. To validate the proposed numerical algorithms, we compare the solutions based on the variational inequality and those based on return mapping algorithm, computed for the same Prager kinematic hardening law.     

Structured inspections of code

Cleanroom programming and code inspections independently provide evidence that it is more efficient to postpone the testing of code to a later stage than is usually done. This paper argues that an additional gain in quality and efficiency of development can be obtained by structuring inspections by means of an inspection protocol. The written part of such a protocol is prepared by the programmer before the inspection. It is modelled on Floyd's method for the verification of flowcharts. However, the protocol differs from Floyd's method in being applicable in practice. Structured inspections gain this advantage by not attempting to be a proof; they are no more than an articulation of existing forms of inspection. With the usual method of structured programming it may be difficult to prepare the inspection protol. On the other hand, ‘assertion-driven programming’ (of which an example is included in this paper) not only facilitates protocol preparation, but also the coding itself.     

Mixed protein-templated luminescent metal clusters (Au and Pt) for H2O2 sensing

A simple and cost-effective method to synthesize the luminescent noble metal clusters (Au and Pt) in chicken egg white aqueous solution at room temperature is reported. The red-emitting Au cluster is used as fluorescent probe for sensitive detection of H₂O₂.     

Optimization of factors affecting esterification of mixed oil with high percentage of free fatty acid

Increased environmental awareness and depletion of resources are driving industry to develop alternative fuels from renewable sources that are environmentally more acceptable. Biodiesel is a non petroleum based fuel that consists of alkyl esters from transestrification of the refined/edible types of vegetable oils alcohol and alkaline catalysts can be used. These catalysts require anhydrous conditions and feed stocks with low levels of free fatty acids (FFAs). Inexpensive feed stocks are used in biodiesel production to reduce its cost and to get rid of waste oils in environmentally friendly way. These oils may contain high levels of FFAs so it cannot be directly used with the base catalysts currently employed. Acid esterification reduces the FFAs content to the desirable level. The major factors that affect the conversion efficiency of the process are molar ratio of alcohol/oil, amount of catalyst, reaction temperature, catalyst type and stirring speed according to reaction duration. For this study, we used a model acid produced by mixing pure oleic acid with mixed oil (50% sunflower + 50% soybean oil). Methanol was used in the experiments due to its low cost. The best conversion efficiency obtained was 96.6% for a molar ratio of 6:1 at a temperature of 60 °C, 2.5% H₂SO₄ and stirring speed of 300 rpm. Finally, different types of waste cooking oil from home and restaurants were used to study the conversion efficiency compared with optimum conditions calculated for model acid oil to be used in biodiesel production with low cost.     

A p‐Order signed integer‐valued autoregressive (SINAR(p)) model

In this article, we propose an extension of integer‐valued autoregressive INAR models. Using a signed version of the thinning operator, we define a larger class of ‐valued processes, called SINAR, which can have positive as well as negative correlations. Using a Markov chain method, conditions for stationarity and the existence of moments are investigated. In particular, it is shown that the autocorrelation function of any real‐valued AR process can be recovered with a SINAR process, which improves INAR modeling.     

程序设计实践课程将训练目标落实到位的尝试

本文提出大众化教育时代程序设计实践课程分层教学理念,说明保证上规模的训练可达时,照顾能力、兼顾兴趣的实践训练任务设计思考,减少复制的监督与管理措施,以及全面评价的方法,并分析实践效果。