MySQL数据库对并发事件的控制和处理

数据库系统作为信息系统中的基础软件,其安全性问题十分重要,尤其是对于并发事件的控制和处理。该文通过对于MySQL数据库系统的详细作用功能阐述,对其性能功能进行详细的研究后,利用ODBC API和MySQL自带的C API函数来实现MySQL数据库功能调用,使得其能够出现并发事件时,能快速有效的进行数据库的数据控制和处理。     

Estimation of distributions involving unobservable events: the case of optimal search with unknown Target Distributions

We consider the problem of estimating the parameters of a distribution when the underlying events are themselves unobservable. The aim of the exercise is to perform a task (for example, search a web-site or query a distributed database) based on a distribution involving the state of nature, except that we are not allowed to observe the various “states of nature” involved in this phenomenon. In particular, we concentrate on the task of searching for an object in a set of N locations (or bins) {C ₁, C ₂,…, C _N }, in which the probability of the object being in the location C _i is p _i , where P = [p ₁, p ₂,…, p _N ] ^T is called the Target Distribution. Also, the probability of locating the object in the bin within a specified time, given that it is in the bin, is given by a function called the Detection function, which, in its most common instantiation, is typically, specified by an exponential function. The intention is to allocate the available resources so as to maximize the probability of locating the object. The handicap, however, is that the time allowed is limited, and thus the fact that the object is not located in bin C _i within a specified time does not necessarily imply that the object is not in C _i . This problem has applications in searching large databases, distributed databases, and the world-wide web, where the location of the files sought for are unknown, and in developing various military and strategic policies. All of the research done in this area has assumed the knowledge of the {p _i }. In this paper we consider the problem of obtaining error bounds, estimating the Target Distribution, and allocating the search times when the {p _i } are unknown. To the best of our knowledge, these results are of a pioneering sort - they are the first available results in this area, and are particularly interesting because, as mentioned earlier, the events concerning the Target Distribution, in themselves, are unobservable.

人居环境伦理观与建筑材料的绿色化

环境伦理观研究的是人与自然之间的伦理关系，人居环境伦理观则是在具体对象上对环境伦理观的细化，研究的对象是人与人居环境的伦理关系。人居环境伦理观赋予人关心和保护人居环境，从而其实也是关心与保护人类自己的特殊职责。人居环境目前正面临着诸多危机，如城市环境污染，室内空气污染等，这意味着人居环境伦理观出现的危机，而这些危机与建筑材料密切相关。针对由于建筑材料引起的人居环境危机，提出了改善人居环境质量的途径之一，就是建筑材料的绿色化。     

金融危机下中国钼加工业发展的思考

金融危机影响全球钼加工业经济,通过对中国钼加工业面临的挑战与机遇分析,指出金融危机下中国钼加工业的发展应拓宽钼的应用领域,突破加工瓶颈,促进产业升级,提出了理念创新、人才战略和有序发展等建议。     

基于遗传优化加权相关向量机的网络热点预测模型

为了提高网络热点事件的预测精度,提出一种基于遗传优化加权相关向量机的网络热点事件预测模型(GA-WRVM)。首先对每个样本数据的噪声方差加上一个权值系数得到加权相关向量机,然后用组合核函数代替相关向量机的单一核函数,并采用遗传算法对核参数进行优化建立预测模型,最后利用网络热点数据进行仿真实验分析。结果表明,相对于神经网络和支持向量机,GA-WRVM降低了网络热点事件的预测误差,获得了更高的网络热点预测精度,具有更强的泛化能力。     

弱点状多运动目标实时跟踪技术研究

根据确认的众多量测和众多目标跟踪窗之间的几何关系,引入确认矩阵并计算所有联合事件及其对应的参数,不论量测是否落入跟踪窗相交区域,根据JPDA算法计算每一个量测与其可能的各个源目标之间互联的概率。将互联的概率与Kalman滤波器相结合从而完成对每一个目标的预测和更新。理论及实验结果表明,该算法适用于序列图像密集杂波环境下的全程跟踪,并取得了一定的理论和仿真结果。     

基于多尺度一维卷积神经网络的光纤振动事件识别

针对相位敏感光时域反射(Φ-OTDR)分布式光纤振动传感系统如何对振动事件进行高效准确识别的问题,本文提出了一种基于多尺度一维卷积神经网络(MS 1-D CNN)的振动事件识别方法。该方法将原始振动信号经过预加重、归一化和谱减降噪的预处理操作后得到的一维信号,直接通过MS 1-D CNN实现端到端的振动信号特征的提取和识别。MS 1-D CNN在提取入侵振动信号特征时可兼顾信号时间和频率尺度,利用全连接层(FC layer)和Softmax层完成最终的识别过程,与二维卷积神经网络(2-D CNN)和一维卷积神经网络(1-D CNN)相比减少了待定参数数量。对破坏、敲击和干扰三类目标振动事件的光纤振动传感信号识别结果表明,MS 1-D CNN的识别正确率与2-D CNN相近,达到了96%以上,而处理速度提升一倍,在保持识别性能的前提下,有利于提高振动事件识别的实时性。     

Assembly of the Complete Mitochondrial Genome of Gelsemium elegans Revealed the Existence of Homologous Conformations Generated by a Repeat Mediated Recombination

Gelsemium elegans (G. elegans) is a Chinese medicinal plant with substantial economic and feeding values. There is a lack of detailed studies on the mitochondrial genome of G. elegans. In this study, the mitochondrial genome of G. elegans was sequenced and assembled, and its substructure was investigated. The mitochondrial genome of G. elegans is represented by two circular chromosomes of 406,009 bp in length with 33 annotated protein-coding genes, 15 tRNA genes, and three rRNA genes. We detected 145 pairs of repeats and found that four pairs of repeats could mediate the homologous recombination into one major conformation and five minor conformations, and the presence of conformations was verified by PCR amplification and Sanger sequencing. A total of 124 SSRs were identified in the G. elegans mitochondrial genome. The homologous segments between the chloroplast and mitochondrial genomes accounted for 5.85% of the mitochondrial genome. We also predicted 477 RNA potential editing sites and found that the nad4 gene was edited 38 times, which was the most frequent occurrence. Taken together, the mitochondrial genome of G. elegans was assembled and annotated. We gained a more comprehensive understanding on the genome of this medicinal plant, which is vital for its effective utilization and genetic improvement, especially for cytoplasmic male sterility breeding and evolution analysis in G. elegans.     

静电及其研究进展

参考人体行走电压的测试标准IEC 61340-4-5, 搭建了电缆由线轴上绕下并在地板上拖拽积累的电压的测试系统, 测量了六类非屏蔽网线的电压波形.基于实测电缆电压波形, 提出了电缆电压的RC等效电路模型, 并分析了模型参数对电缆电压时域波形的影响.进行了电缆充电后对金属靶的放电实验, 测量了电缆放电事件的电流波形、瞬态电场和瞬态磁场波形, 分析了电缆放电事件对电子设备的影响.根据测量的电缆放电事件的电流波形, 对比了GJB 151B中CS 115电缆束注入脉冲激励传导敏感度的电流波形, 二者电流波形有一定的相似性, 但是对于较长电缆在电流的强度和宽度方面都会大于CS 115规定的限值.因此, 提出了电缆放电事件的防护方法, 并对相关标准的改进方面提出了初步建议.     

计算机网络安全与防护

随着计算机的发展,互联网的共享性,开放性以及互联程度的不断扩大。其中lnternet的广泛普及,商业数字货币,网络银行等一部分网络新业务的迅速兴起,使得计算机网络的安全问题越来越显得重要,本文归纳总结,提出网络信息中的一些安全防护策略。