Compact, reliable asymmetric optical configuration for cost-effective fabrication of multiplex dot matrix hologram in anti-counterfeiting applications

This study presents a compact optical configuration that can generate a multiplex dot-matrix hologram with complex interlaced images for anti-counterfeiting applications on valuable paper. Varying the orientation of the interference plane can enable the multiplex hologram to be recorded without changing the interference angle of two laser beams. With its simple asymmetric optical setup, a multiplex hologram with many interlaced images can be efficiently fabricated, increasing the cost of imitation. Experimental details of the asymmetric optical setup are also described.     

证券价格按几何布朗运动变化的微观解释

金融市场研究中经常不加解释地假设证券价格按几何布朗运动变化 .本文通过假定投资者要求来自证券的期望收益率与证券价格无关 ,在理想市场的前提条件下 ,对证券价格运动将遵循有漂移率的几何布朗运动给予严格的证明 .     

Phase-Only Encryption and Single Path Decryption System Using Phase-Encoded Exclusive-OR Rules in Fourier Domain

A phase-only encryption scheme using phase-encoded exclusive-OR (XOR) rules in a Fourier plane and a single path decryption system are presented. To generate phase-only encrypted data, a zero-padded original image, multiplied by a random phase image, is Fourier transformed and its real-valued data is encrypted with key data by using phase-encoded XOR rules. Since the original information is encrypted on the Fourier plane, the proposed encryption is more tolerant to loss of key information by scratching or cutting than previous XOR encryption in a space domain. A decryption is simply performed based on 2-f setup with spatial filter by Fourier transform for multiplication phase-only encrypted data with phase-only key data. Due to single path architecture without a reference wave, the proposed system is resistant to mechanical vibrations and fluctuation. Numerical simulations have confirmed the validity of the proposed encryption scheme and simple decryption architecture.     

透射式跑道能见度激光测量仪的研究

介绍了一种利用激光测量跑道水平及斜视能见度的智能化仪器。该仪器主要由光学系统、信号放大与处理系统及显示系统三部分组成。简要介绍了该仪器的基本结构、工作原理和主要技术指标，讨论了其中的技术难点及其相应的解决办法。     

基于园区网络的主动安全模型设计与研究

从现行典型园区网络安全设计方案入手，结合其在安全防范解决方案上存在的问题，提出了一种网络主动安全模型；在全局网络安全认识的基础上．阐述了模型组成部件的功能定义和网络主动安全实现流程；采用统一网络入口认证、网络知识发现及资源有效控制、沟通等手段，解决了现行网络安全设计中存在的恶意攻击行为源头定位困难，以及信息安全司法取证不准、网络资源安全被动防护、网络灾难快速反映能力差等问题．实验结果表明，该设计方案具有较好的可行性和实用性．     

Building and analyzing the US airport network based on en-route location information

From a complex network perspective, this study sets out two aims around the US airport network (USAN) which is built from en-route location information of domestic flights in the US. First, we analyze the structural properties of the USAN with respect to its binary and weighted graphs, and second we explore the airport patterns, which have wide-ranging implications. Results from the two graphs indicate the following. (1) The USAN exhibits scale-free, small-world and disassortative mixing properties, which are consistent with the mainstream perspectives. Besides, we find (2) a remarkable power relationship between the structural measurements in the binary graph and the traffic measurements in the weighted counterpart, namely degree versus capacity and attraction versus volume. On the other hand, investigation of the airport patterns suggests (3) that all the airports can be classified into four categories based on multiple network metrics, which shows a complete typology of the airports. And it further indicates (4) that there is a subtle relationship between the airport traffic and the geographical constraints as well as the regional socioeconomic indicators.     

Nutritional potential of edible Russula species from Alédjo Wildlife Reserve (AWR)

In order to contribute to the valorisation of wild fungi whose nutritional potential, although considerable, is not sufficiently known in some countries such as Togo, a study has been carried out on Russula species. The diversity of Russula species from Alédjo Wildlife Reserve has been assessed using a focused inventory in woodlands dominated by Isoberlinia doka Craib & Stapf, Isoberlinia tomentosa (Harms) Craib & Stapf, Monotes kerstingii Gilg, Uapaca togoensis Pax and gallery forests dominated by Berlinia grandiflora (Vahl) Hutch & Dalz and Uapaca guineensis Müll. Ethnomycological surveys have been carried out among Tém and Kabyè, two riparian ethnic groups that are mainly represented. Biochemical analyses have been carried out using the AOAC method. Fifteen (15) taxa of edible Russula species are commonly used by Tém and Kabyè people living along the Alédjo Wildlife Reserve among which thirteen (13) taxa have been identified up to species level. R. oleifera is eaten by all interviewed people in both sociolinguistic groups (Fr = 100%) followed by R. compressa (Fr = 92.31%), R. ochrocephala (Fr = 87.18%) among Tém people and R. ochrocephala (Fr = 91.67%), R. compressa (Fr = 83.33%) among Kabyè people. Five (05) new species of edible Russula have been identified for the first time in Togo. The Russula species analysed have been rich in macronutrients with contents ranging from 2.88 g/100 g of dw for fat to 65.83 g/100 g of dw for total carbohydrates. In addition, these Russula species have shown a relatively high mineral content with contents ranging from 405.70 mg/100 g of dw for Ca to 2784 mg/100 g of dw for K. Furthermore, the results have revealed that Russula species analysed are a source of energy with 309.50 Kcal/100 g of dw. The edible Russula species analysed can thus contribute to food security in Togo.     

石化厂区有毒气体泄漏在线监测平台的构建

针对石化厂区在生产过程中可能发生有毒气体泄露带来的生产安全问题,构建了石化厂区有毒气体在线监测平台。该平台是由PC监控中心、网络监控中心、ARM便携式终端、安卓手机客户端组成。实现对石化厂区中有毒气体及环境参数的实时、在线监测和预警,使生产管理人员掌握石化厂区的有毒气体实时动态信息,对可能引发危险事故的因素及时排除,把危险控制在始发阶段,以实现化工生产的安全、持续、高效进行。测试结果表明该平台能实现所设计的各项功能,并具有良好的稳定性、安全性和实用性。     

公共安全视域下精神药物光谱学无损分类

该文对苯二氮类和吩噻嗪类镇静安眠药样品的红外光谱数据进行采集,构建了不同数据分类模型并对比了不同波段光谱数据集对其分析准确率的影响。结果表明,借助贝叶斯判别分析的基于全波段数据集的二阶导数模型分类效果优于其他单一模型,对于苯二氮类和吩噻嗪类两个不同类型精神药物的总体分类准确率达92.7%。借助贝叶斯判别分析的基于全波段和指纹区融合数据集的二阶导数融合模型分类效果最佳,对苯二氮类和吩噻嗪类两个不同类型精神药物的总体分类准确率达到100%;对苯二氮类和吩噻嗪类中不同种类精神药物的总体分类准确率则分别达到96.7%和100%。该研究实现了不同类型及同一类型不同种类镇静安眠药的快速准确定性分析,为此类管制类药物走私案件的准确定性提供了一定的技术支持。     

食品安全分析样品前处理-快速检测联用方法研究进展

综述了近年来传感器、可视化分析、便携光谱、酶联免疫检测及便携气相色谱等食品安全快速检测技术的研究现状,以及食品安全分析中样品前处理-快速检测联用技术的研究进展,为发展选择性好、准确度高、可定量的新型食品安全快速检测技术提供参考。