Ruin Probability in a Semi-Markov Risk Model with Constant Interest Force and Heavy-Tailed Claims

In the present paper, we consider a kind of semi-Markov risk model (SMRM) with constant interest force and heavy-tailed claims, in which the claim rates and sizes are conditionally independent, both fluctuating according to the state of the risk business. First, we derive a matrix integro-differential equation satisfied by the survival probabilities. Second, we analyze the asymptotic behaviors of ruin probabilities in a two-state SMRM with special claim amounts. It is shown that the asymptotic behaviors of ruin probabilities depend only on the state 2 with heavy-tailed claim amounts, not on the state 1 with exponential claim sizes.     

预警信息引导条件下雷达最优搜索空域研究

提出了一种基于预警引导信息的弹道导弹防御跟踪制导雷达搜索空域最优划分模型,从搜索空域的静态划分和动态更新2个方面同时进行最优化,实现了弹道目标高速运动条件下,跟踪制导雷达对目标分布区域的连续有效覆盖,提高了雷达对目标的截获性能。最后给出了仿真结果,验证了该方法的有效性。     

强激光对典型激光制导光电探测器的干扰效应研究

为了达到对激光制导武器的有效干扰目的,需要分析强激光对典型激光制导光电探测器的干扰效应。理论分析和数值计算表明四象限光电二极管和成像型CCD的光学饱和阈值较低,很容易达到光学饱和。在功率密度10MW/cm2,脉冲宽度5ns的单脉冲激光辐照下即可产生300K的温升,在多脉冲温升的累积作用下,光电探测器的基底材料很容易达到熔点,从而造成不可逆的永久损伤。     

Parallel spatial-temporal convolutional neural networks for anomaly detection and location in crowded scenes

Anomaly detection and location in crowded scenes have attracted a lot of attention in computer vision research community recently due to the increased applications of intelligent surveillance improve security in public. We propose a novel parallel spatial-temporal convolution neural networks model to detect and localize the abnormal behavior in video surveillance. Our approach contains two main steps. Firstly, considering the typical position of camera and the large number of background information, we introduce a novel spatial-temporal cuboid of interest detection method with varied-size cell structure and optical flow algorithm. Then, we use the parallel 3D convolution neural networks to describe the same behavior in different temporal-lengths. That step ensures that the most of behavior information in cuboids could be captured, also insures the reduction of information unrelated to the major behavior. The evaluation results on benchmark datasets show the superiority of our method compared to the state-of-the-art methods.     

A novel organizing scheme of single topic user group based on trust chain model in social network

Social network sites (SNS) presently face the task of grouping users into small subsets within themselves. In this study, an organizing scheme for single‐topic user groups is proposed for facilitating user sharing and communicating under common interests. The main rationales of the proposed scheme are (1) only an influential single topic is selected through its impact evaluation to attract users; (2) only the users having high degree of interest, explicit or implicit, on the topic should be grouped; and (3) trustworthy relationships among users are taken into consideration to enlarge the scale of user group. The proposed organizing scheme comprises 3 features: topic impact evaluation, interest degree measurement, and trust chain‐based organizing. The main structure of our proposed scheme is (1) an overview of the proposed scheme and its formal related definitions; (2) a topic impact evaluation method, ie, an importance evaluation and a popularity calculation; (3) a user interest degree measurement method, ie, explicit and implicit interest evaluation with dynamic factors included; (4) a trust chain calculation method based on the topology features of the trust chain; (5) an organizing algorithm for single topic user group, and finally, some experimental results and discussions to illustrate the effectiveness and feasibility of our scheme.     

化学竞赛选手失利体验的心理学分析与启示——基于教育现象学的个案研究

采用现象学研究方法,通过研究一名化学竞赛选手失利时的心理体验,了解竞赛选手的参赛动机、参赛心态、学习兴趣、学习压力等方面问题,进而探寻其教育意义。对学科竞赛与资优生培养得出一些思考与启示。     

Altium Designer15在电路设计的应用

在电路设计中,简单电路可以用手稿或一些办公室软件来实现,但对于复杂电路来说,则需要使用专业的EDA辅助设计软件来完成,如电路原理图(Sch)与印制电路板(PCB)文件的制作等设计工作。随着电子技术的不断创新,各种新型器件层见迭出,电路变得也越来越繁杂,传统设计方法已无法完成高密度设计要求。本文以FPGA实验教学开发板的电路进行设计为例,通过使用AltiumDesigner(以下简称AD)15这款辅助设计软件进行电路设计,不仅可以增加学生学习乐趣,还能提高动手能力,为毕业以后从事同专业工作夯实基础。     

Multiattribute‐based routing for lifetime maximization in opportunistic mobile social networks

With the advancement in wireless technology and portable devices, smart phones have become one of the belongings of human being. People share their data online, but it has limitations due to transmission range and mobility. Yet opportunistic mobile social network enables users to share data online even if there is no connected path between source and destination. The widespread use of mobile phones equipped with WiFi, Bluetooth, and several other components and contact opportunities among humans bridge the gap between internet available and nonavailable area. In this paper, we have proposed a new routing approach which utilizes both spatial and temporal attributes of user such as probability to meet a particular location and remaining intercontact time between two nodes to select better relay nodes. Generally, users visit different locations such as sports stadium and mall, with varying probability. Users with similar interest form group, and each user has different intercontact time with other users according to their point of interest and visiting pattern. By utilizing multiattributes, different forwarding strategies have been devised for both inter and intragroup routing. The proposed work “point of interest (PoI)‐based routing” is implemented in Opportunistic Network Environment simulator, and the performance is analysed in terms of delivery rate, latency, overhead, goodput, and energy consumed. The simulation results show that PoI diminishes 23% of overhead and yields 24% improvement in goodput over the state‐of‐the‐art protocol. Thus, the simulation results reveal that our proposed work provides the balance between routing performance and resource consumption.     

AN OPTIMAL INVESTMENT／CONSUMPTIONPROBLEM WITH HIGHER BORROWING RATE

In this paper, optimal investment and consumption decisions for an optimal choiceproblem in infinite borizon are considered, for an investor who has available a bank account anda stock whose price is a log normal diffusion. The bank pays at an interest rate r for any de-posit, and takes at a larger rate / for any loan. As in the paper of Xu Wensheng and ChenShuping in JAMS(B), where an analogous problem in finite horizon is studied, optimal strategies are obtained via Hamilton-Jacobi-Bellman (ladE) equation which is derived from dynamic c1-programming principle. For the specific HARA case, i.e. U(t,c)=e^-βtc^1-R/1-R, this paper getsthe optimal consumption and optimal investment in the form of c^‘1 =β -^-g/Rwi and π^‘1= b -- γ / Rσ^2wr, with γ1,=max{γ,min{γ‘,b--Rσ^2‘} },^-g=(1--R)[γ (b-γ)^2/2Rσ^2]. This result coincides with the classical one under condition γ‘ ≡γ.     

基于主动学习和否定选择的垃圾邮件分类算法

针对现在网络上泛滥的垃圾邮件问题,本文结合主动学习方法和否定选择算法提出了一种二类文本分类方法：主动否定学习算法.根据用户少量标注建立双向兴趣集,利用否定选择算法的自体异常检测机制改善主动学习中的采样策略,并将双向兴趣集作为检测器,新增样本集作为自体集,对两者进行异常匹配.本文算法与在线垃圾邮件快速识别方法、增强差异性的半监督协同分类算法、垃圾邮件过滤方法、基于人工高免疫的多层垃圾邮件过滤算法和在线主动多领域学习方法在六个常用邮件语料集上进行了分析比较,结果表明本文算法具有较高的准确率、召回率、分类精度,和较低的用户标注负担.使用用户个性喜好转换为双向兴趣特征的方式有助于提高算法的分类能力;利用异常检测匹配选取未知类别特征的方式,有效地降低了用户标注负担.