士官本科程序设计课程教学探索

针对直招士官专升本学员的特点,给出了结合学制学时进行程序设计课程总体设计的具体思路,结合模块化方法对教学内容进行整体优化的详细方案,以及以活跃理论课、强化实验课、开展讨论课、完善配套微课程和学员互助为核心的教学模式方法改革举措。为提高士官本科学员程序设计课程的教学效果,进行了教学改革的具体探索,经验对其他课程也具有一定的参考价值。     

物联网访问控制策略探析

随着计算机技术的快速发展,各种物联网应用在人们生活中越来越多,因而物联网安全问题也更加引人关注。针对物联网安全中的访问控制问题,分析物联网分层结构中各层的安全需求,给出联网的环境下的访问控制策略供参考。     

聚芳硫醚类树脂的研究及其产业化

主要介绍了几种聚芳硫醚类高性能树脂(聚苯硫醚、聚芳硫醚砜、聚芳硫醚酮、聚芳硫醚酰亚胺以及聚芳硫醚腈)的性能、研究动向以及产业化情况;并对今后聚芳硫醚类树脂的研究、发展趋势进行了预测。     

聚甲醛耐老化性能及其改进研究

以研制耐候性聚甲醛为目标，将自制高分子改性剂、其它改性剂与聚甲醛共混(POM)以提高POM的耐老化性。通过拉伸强度、断裂伸长率、冲击强度和色差的测定，比较了未改性聚甲醛和改性聚甲醛的耐紫外光老化、热氧老化和热水老化性能，结果表明：自制改性剂与其它改性剂共混用于聚甲醛，能显著改善聚甲醛的稳定性及耐老化性。     

工艺条件对玻纤增强ABS材料力学性能的影响

通过对30％玻纤增强ABS材料微观形态观察和分析，探寻了加工工艺条件和加入马来酸酐接枝ABS对材料力学性能的影响，结果表明，加入马来酸酐接枝ABS可明显改善基体材料与玻纤的粘结状况，使力学性能得到较大幅度的变化，加工温度的提高和适当的螺杆转速可提高玻纤在基体中的分散性，尽管玻纤分散性较好的材料其玻纤含量较低，玻纤长度较短，但仍使力学性能得到改善。     

基于语言结构和情感极性的虚假评论识别

随着电子商务的发展,识别网络中的虚假评论意义重大。传统的启发式策略或全监督学习算法不能有效地解决该问题。虚假评论与真实评论在语言结构和情感极性上存在差异,提出基于遗传算法对语言结构及情感极性特征进行优化选择,并利用选取的特征结合无监督硬、软聚类算法对虚假评论进行识别。实验结果验证了所提算法的有效性。     

HTTP-SoLDiER: An HTTP-flooding attack detection scheme with the large deviation principle

HTTP-flooding attack is a much stealthier distributed denial of service （DDoS） attack, challenging the survivability of the web services seriously. Observing the web access behavior, we find that the surfing preference of normal users is much more consistent with the webpage popularity than that of malicious users. Based on this observation, this paper proposes a novel detection scheme for HTTP-flooding （HTTP-SoLDiER）. Specifically, HTTP-SoLDiER first quantifies the consistency between web users surfing preference and the web- page popularity with large-deviation principle. Then HTTP-SoLDiER distinguishes the malicious users from normal ones according to the large-deviation probability. In practice, the webpage popularity plays a key role in attack detection of HTTP-SoLDiER. Due to the never-ending updating of the webpage content and the disturbance induced by attackers, the webpage popularity often varies over time. Thus, it is critical for HTTP-SoLDiER to dynamically update the webpage popularity. We design a reversible exponentially weighted moving average （EWMA） algorithm to solve the problem. Finally, we evaluate the effectiveness of this scheme in terms of true positive （TF） and false positive （FP） probabilities with NS-3 simulations. The simulation results show that HTTP-SoLDiER can detect all random HTTP-flooding attackers and most of the perfect-knowledge HTTP-flooding attackers at little false positive.     

马钢CSP卷取机夹送辊控制的优化措施

针对马钢CSP热轧卷取夹送辊的缠辊故障,提出相应的优化改造措施。     

A novel initial ranging algorithm for OFDMA systems using smart antenna

To improve the capacity of initial ranging （IR） users simultaneously accessing into network and enhance the performance of the IR, a novel IR algorithm is presented for the orthogonal frequency division multiple access systems with the smart antenna. The beamforming weight vectors provided by the antenna array are introduced for the IR users, and the procedures of the multiuser parameter estimation and the interference cancellation are designed. The proposed method can improve the accuracy of the channel estimation of active paths and efficiently reduce the residual multiple access interference. Simulation results show that the proposed method has a much better performance than the available successive multiuser detection and interference cancellation algorithm and accommodates more active ranging users simultaneously accessing into a cell.