基于改进D-S证据理论的数据融合目标分类

首先采用分类算法对MSTAR数据集进行十类目标分类识别、三类目标的变体分类识别,然后根据分类调参过程中的先验知识修正证据即分类器输出,构造基本置信函数,并采用改进的合成规则即基于冲突系数K和Pignistic概率距离相结合的冲突度量方法,对冲突证据采用按比例分配冲突度的合成规则进行合成。未融合时,三类目标的变体分类准确率最高为93.553%,融合后三类目标变体分类识别率为95.092%,提升幅度约是理想状态的37%。     

结合新型模糊支持向量机和证据理论的多传感器水质数据融合

在多传感器水质数据融合领域,证据理论是有效的数据融合方法之一,但基本概率分配一般不易确定,从而使数据融合能力难以有效发挥。支持向量机是统计学习理论之上的高级分类算法,具有普适性和全局优化等特点,但输出的基本概率分配有待进一步提高。提出了一种基于证据理论和新型模糊支持向量机相结合的数据融合方法,通过建立基于分类超平面距离的模糊隶属度,训练模糊支持向量机提高传统支持向量机的基本概率分配,并结合证据理论进行海河水质数据融合。通过证据理论分别结合支持向量机和模糊综合评价法与上述方法进行对比实验,经精度、平均绝对百分误差、均方根误差等指标验证,精度提高10. 5%,表明所提方法是一种可靠的多传感器的水质融合方法,较其他方法具有更高的融合精度。     

Dempster-Shafer Evidence Theory and Study of Some Key Problems

As one of the most important mathematical methods, the Dempster-Shafer (D-S) evidence theory has been widely used in date fusion, risk assessment, target identification, knowledge reasoning, and other fields. This paper summarized the development and recent studies of the explanations of D-S model, evidence combination algorithms, and the improvement of the conflict during evidence combination, and also compared all explanation models, algorithms, improvements, and their applicable conditions. We are trying to provide a reference for future research and applications through this summarization.     

裂解气相色谱-质谱分析火场残留物中助燃剂

通过对火灾现场助燃剂及其燃烧残留物进行分析，开展了基于裂解气相色谱-质谱法（PyGC-MS）的火场助燃剂分析方法。选取了汽油和柴油2种助燃剂以及棉布和聚对苯二甲酸乙二醇酯（PET）塑料2类载体，制备了助燃剂与载体的混合燃烧残留物。利用热分析技术确定样品的特征性温度，并对分析条件进行优化与选择。通过闪蒸分析和裂解分析的分步裂解方法，对样品进行了PyGC-MS分析。实验结果表明，PET载体原样燃烧残留物的裂解产物共有35个组分，而PET载体与汽油混合燃烧残留物和PET载体与柴油混合燃烧残留物的裂解产物只有25个组分，且各裂解产物的种类和含量均不相同。该法可对同一载体的自身燃烧残留物和与助燃剂混合燃烧残留物进行区分，适用于火灾残留物中助燃剂的分析，可对火场中是否存在助燃剂进行判别，为火灾性质的判断和火灾调查工作提供科学依据。     

Applications of synchrotron radiation in forensic trace evidence analysis

Synchrotron radiation sources have proven to be highly beneficial in many fields of research for the characterization of materials. However, only a very limited proportion of studies have been conducted by the forensic science community. This is an area in which the analytical benefits provided by synchrotron sources could prove to be very important. This review summarises the applications found for synchrotron radiation in a forensic trace evidence context as well as other areas of research that strive for similar analytical scrutiny and/or are applied to similar sample materials. The benefits of synchrotron radiation are discussed in relation to common infrared, X-ray fluorescence, tomographic and briefly, X-ray diffraction and scattering techniques. In addition, X-ray absorption fine structure analysis (incorporating XANES and EXAFS) is highlighted as an area in which significant contributions into the characterization of materials can be obtained. The implications of increased spatial resolution on microheterogeneity are also considered and discussed.     

Sampling strategies for the analysis of glass fragments by LA-ICP-MS Part I. Micro-homogeneity study of glass and its application to the interpretation of forensic evidence

The authors have previously reported the use of laser ablation ICP-MS as a powerful analytical tool for elemental analysis of glass. LA is a simpler, faster and less intrusive sample introduction method than the conventional solution ICP-MS. Due to the minute amount of material removed in LA (∼300 ng, 50 μm crater size), the analyst should be aware of special sampling considerations such as characterization of the glass fragments originating from the “known” source, fragment size and selection of the area and surface of ablation.The purpose of this work was to evaluate the micro-homogeneity of the elemental composition of glass samples commonly found in crime scenes like containers, architectural windows and windshields. The set of glasses under study was comprised of 56 fragments originated from glass containers, 28 fragments from automobile windshields and 20 fragments from architectural windowpanes. All fragments were selected with a size smaller than 2 mm² in order to simulate the typical glass fragments transferred from the crime scenarios. A Nd:YAG laser, 266 nm, flat top beam profile was used in single point mode sampling 50 μm spot size for 50 s at 10 Hz (500 shots). In this study, ²⁹Si was used as an internal standard and the standard reference material, SRM NIST 612, was used as a single point external calibrator. In addition, SRM 621 was used as another control standard for the containers set and SRM 1831 for the automobile and architectural window sets due to their very similar matrix with the samples of interest. For each set of glasses, the mean values and standard deviation of 10 replicates (n = 10) of a single fragment were compared with the values obtained from 10 (n = 10) different fragments of glass within the area of interest in order to evaluate whether or not the variation within a glass was bigger than the variation due to the method. In addition, a subset of tempered glasses was evaluated to perform an elemental composition profile within different depths of the fragments. Single shot (one laser pulse per analysis) was also evaluated and its limitations for the forensic analysis of glass are also presented. The results show that float glass is homogenous even at the micro-range level allowing LA-ICP-MS as an alternative technique to perform elemental analysis of glass. However, the variation of elemental composition of headlamps and containers is larger over the source than the instrumental variation due to inherent heterogeneity and therefore specific statistical methods are recommended to compare the glass samples.     

计算机网络管理中维护冲突原因分析及对策

计算机在生活的诸多领域中发挥着重要作用,信息技术的广泛应用,使得计算机与生活之间的联系更加紧密.网络的发展改变了人们的生活方式,给人们带来便利的同时也带来了相应的问题.比如在计算机网络管理中存在的病毒,黑客入侵等,给计算机管理和维护工作带来了一定的困扰.本文就计算机网络管理中维护冲突原因分析及对策作简要阐述.     

电视技术专利审查中公知常识的认定和举证

通过分析专利法中有关公知常识的规定,归纳总结了电视技术领域专利审查实践中公知常识认定和举证的几种常用方式,并且通过电视技术领域的审查案例予以详细的说明,在此基础上对电视技术领域中的审查员、申请人提出一些建议.     

User‐Centric Conflict Management for Media Services Using Personal Companions

In this paper, we propose a user‐centric conflict management method for media services which exploits personal companions for the harmonious detection and resolution of service conflicts. To detect conflicts based on the varying characteristics of individual users, the proposed method exploits the unified context describing all users attempting to access media services. It recommends and mediates users' preferred media contents through a shared screen and personal companions to resolve the detected conflicts. During the recommendation, a list of preferred media contents is displayed on the shared screen, and a personally preferred content list is shown on the user's personal companion comprising the selection of media contents. Mediation assists the selection of a consensual service by gathering the users' selections and highlighting the common media contents. In experiments carried out in a ubiHome, we observed that recommendations and mediation are useful in harmoniously resolving conflicts by encouraging user participation in conflict situations.     

考虑右转机动车影响下的信号交叉口行人过街时间模型

为了弄清信号交叉口右转机动车对行人过街的影响机理,应用穿越间隙理论,分析行人穿越机动车的分布规律,并推导了行人过街时间模型公式,通过定量分析及模型算例,找出了行人过街时间的主要影响因素及其定量关系,模型精度基本满足要求,具有较高的理论和实用价值,为信号交叉口的信号设计,特别是行人专用信号相位的设置、分析和研究提供了新思路和新方法.