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1.
数字隐写技术及发展趋势   总被引:1,自引:0,他引:1  
笔者通过强调数字隐写算法和隐写分析算法间的矛盾统一,介绍数字隐写算法的发展历程和趋势以及国内外的研究现状。重点介绍具有代表性的空域LSB隐写算法和频域JPEG图像隐写算法。通过基本算法、对基本算法的分析方法、基本算法改进措施的顺序,介绍算法的发展历程,分析算法的性能。对当前实验研究的进展和数字隐写技术存在的问题进行说明,并提出一些建设性意见,对隐写技术的发展前景和方向进行展望,指出数字隐写技术会成为密码术的重要补充,在信息安全传输方面发挥巨大的作用。  相似文献   

2.
随着数字视频压缩技术的不断发展,基于数字技术的多媒体监控系统.开始逐步替代传统的图像监控系统基于多媒体监控系统采用数字技术对信号进行采样和压缩,所以它可以实现网络传输,而不用采用传统的视频电缆或者光纤传输,大大节省了成本,同时更容易实现对图像的存储、处理和控制.论文采用嵌入式操作系统,在ARM7平台上实现多媒体的监控.  相似文献   

3.
本文引入了一种基于超分辨率技术的图像增强方法,首先将其用来处理数字CCTV监控图像,并从结果中获取犯罪调查线索,随后又将此技术用来处理电子化后的胶卷照片,也得到了良好的结果.  相似文献   

4.
近年来,古典家具越来越受到人们的青睐。但是目前还未见有关针对古典文物家具数字博物馆的相关研究报道。本文首先介绍了数字博物馆的特点以及所构建的明清古典文物家具数字博物馆,然后运用基于混沌理论的Logistic映射置乱方法对水印图像进行加密,以及变换域算法中基于DCT域的数字水印方法对数字博物馆的数字图像进行了版权保护,并利用Matlab软件进行水印图像的嵌入、提取和检测实验,取得了较好的效果,说明数字水印技术在文物家具图像版权保护方面具有很好的作用。  相似文献   

5.
正■万能解码、混合接入、高级图控、无限扩展产品名称:高清网络数字矩阵产品型号:PE70公司全称:浙江红苹果电子有限公司公司网址:www.pearmain.cn一、研发背景矩阵作为视频监控系统的核心部分,它的一个重要功能就是将任意一路视频图像切换到任一输出通道。视频矩阵在安防领域应用广泛,随着整个安防行业高清化、网络化趋势的愈演愈烈,矩阵逐渐被划分为两大类:一类是传统的模拟矩阵,另一类是基于数字技术的矩阵。其中,数字矩阵  相似文献   

6.
胡彦 《中国安防》2006,(4):71-73
杭州市公安局自2003年开展了全市范围的治安动态监控系统建设,并成功利用数字技术,将各区、县的监控图像汇集、整合到统一的数字平台,实现了全市监控图像的信息共享,这个数字平台就是"治安动态监控系统共享平台"(以下简称"共享平台").共享平台已在公安工作中发挥出巨大的作用,并为监控图像共享给政府其他部门打下了良好的基础.下面就共享平台的开发背景、基本技术路线、实施及应用过程中的经验等几个方面,讲述关于我们在共享平台实施过程中探索到的一些经验.  相似文献   

7.
近年来,在安防图像监控领域中出现了不少数字硬盘录像机,它们以清晰度高、操作方便、硬盘存储等优点受到用户欢迎.数字视频产品取代传统的模拟产品已成为监控行业发展的必然趋势,但面临联网的难题.随着宽带网络的兴起,对安防图像监控产品提出了网络化要求.目前有许多硬盘录像机也有一些网络接口,如ADSL或LAN接口等,但是整个设计还是基于单机功能的.市场呼唤面向宽带IP网络设计的图像监控产品,也就是真正意义上的"MPEG over IP/以太网/ATM",使基于MPEG技术压缩的数字图像,不但是从单机传输到单机,而是在巳建成的宽带IP网(如百兆或千兆以太网)上达到能有几百个用户同时监控几百台摄像机的水准,在宽带网上平滑、通畅、稳定地运行.  相似文献   

8.
一、高清监控的发展视频监控经过几代的发展逐渐由模拟监控发展到数字监控。标清时代的监控解决了"看得见"的问题,随着高清监控的发展又解决了"看得清"的问题,后来智能分析技术在高清图像基础上实现了对图像的智能识别,所以,高品质的图像对整个监控系统来说尤为重要。2010年主流安防公司纷纷推出了  相似文献   

9.
一、引言 近年来,随着平安城市等大型视频监控系统向网络化、高清化、集成化发展,传输系统也在市场需求的推动下开始了技术升级,作为其中的一个重要组成部分,光端机的应用及发展也一直为业内所关注. 在视频监控系统中,监控图像的传输是整个系统的一个至关重要的环节,选择何种介质和设备传送图像将直接关系到监控系统的质量和可靠性,传输部分是整个监控系统的中枢神经,传输网络的设计和选择决定了监控系统的可靠性和可扩展性.视频监控技术在我国的上世纪80年代开始逐渐兴起,基于传输介质的不同先后出现了在同轴电缆传输介质下的短距离传输方式,光纤介质下的模拟视频远距离模拟方式传输、模拟视频远距离数字方式传输和光平台传输方式.  相似文献   

10.
过去,一提起图像监视,不论规模大小,大部分指的是监视摄像机(拍摄)、监视器(看)、切换器(制作)和VTR(记录)。现在,摄像机处理来自CCD的图像信号的技术变成了数字处理技术,切换器也由只使用视频信号的切换技术改为使用数字技术的多画面显示技术。但是,其结果,任何一个I/F也都是模拟(NTSC)的,  相似文献   

11.
在分析500kV变电站主变压器消防系统的现状,比较3类消防系统优缺点的基础上,详细论述了主变排油注氮装置的结构组成、工作原理、参数计算、控制系统设计以及需要注意的事项等,为下一步排油注氮装置的推广应用打下基础.  相似文献   

12.
为克服传统危险与可操作性(HAZOP)定性分析方法在复杂操作、间歇作业等过程中使用的局限性,提出在传统HAZOP定性分析方法的基础上结合What-if(故障假设)方法,对人的不安全行为和操作规程不完备所导致的风险后果分析作出补充。详细说明其技术原理、工作流程等使用细节,系统阐述该方法与传统HAZOP定性分析方法的区别,并在某延迟焦化装置的除焦操作的风险分析中应用。经分析,识别出在“给水-泡焦”节点,有“操作规程错误”场景2项,“操作规程不具体”场景1项,不存在“操作人员未按操作规程执行”场景。研究结果表明:本文方法有效且具有较好效果,可以广泛应用于操作规程/作业指导书审查、作业过程隐患排查等方面,帮助企业开展操作层面的风险识别与管理,提升企业的生产安全水平。  相似文献   

13.
Introduction: Pedestrian fatalities in the United States increased 45.5% between 2009 and 2017. More than 85% of those additional pedestrian fatalities occurred at night. Method: We examine Fatality Analysis Reporting System (FARS) data for fatal pedestrian crashes that occurred in the dark between 2002 and 2017. Within-variable and before/after examinations of crashes in terms of infrastructure, user, vehicle, and situational characteristics are performed with one-way analysis of variance (ANOVA) and two-sample t-tests. We model changes in crash characteristic proportions between 2002–2009 and 2010–2017 using linear regressions and test for autocorrelation with Breusch-Godfrey tests. Results: The increase in fatal nighttime pedestrian crashes is most strongly correlated with infrastructure factors: non-intersection unmarked locations (saw 80.8% of additional fatalities); 40–45 mph roads (54.6%); five-lane roads (40.7%); urban (99.7%); and arterials (81.1%). In addition, SUVs were involved in 39.7% of additional fatalities, overrepresenting their share of the fleet. Increased pedestrian alcohol and drug involvement warrant further investigation. The age of pedestrians killed increased more (18.1%) than the national average (3.2%). Conclusions: By identifying factors related to the increase in nighttime pedestrian fatalities, this work constitutes a vital first step in making our streets safer for pedestrians. Practical Applications: More research is needed to understand the efficacy of different solutions, but this paper provides guidance for such future research. Engineering solutions such as road diets or traffic calming may be used to improve identified infrastructure issues by reducing vehicle speeds and road widths. Rethinking vehicle design, especially high front profiles, may improve vehicle issues. However, the problems giving rise to these pedestrian fatalities are likely a result of not only engineering issues but also interrelated social and political factors. Solutions may be correspondingly comprehensive, employing non-linear, systems-based approaches such as Safe Systems.  相似文献   

14.
为了研究原位煤体渗透性的各向异性特征,以山西潞安常村矿3号煤层圆柱试样为对象,利用TCQT-Ⅲ型低渗煤层气相驱替增产试验装置,对煤样进行加载,并以氮气注入压力2.0 MPa的条件下,分析垂直层理和平行层理2个方向的煤体变形和渗透率变化特征。实验结果表明:煤样在加载过程中,平行和垂直层理煤样渗透率均随着有效应力的增大而减小,平行层理方向的渗透率始终大于垂直层理方向,应力加载初期渗透率急剧下降,最后逐渐趋于平缓;径向应变的增加量与渗透率呈正相关性,且平行层理相关性大于垂直层理;沿平行层理方向的裂隙度大于沿垂直层理方向,沿垂直层理方向的应变量大于沿平行层理方向;应变增加量均随有效应力的增加而逐渐减小。研究结果可为煤层井网布置及优化提供参考。  相似文献   

15.
森林地表火蔓延模拟方法及其计算机实现   总被引:6,自引:1,他引:5  
杜飞  候遵泽  刘家琦 《火灾科学》2001,10(4):204-208
进行了森林火蔓延的研究,对传统的经验公式和模型进行改进,明显发现改进的模型有更好的结果,用计算机巧妙准确地实现了模拟模型,在风力不是特别大,地形变化不是特别剧烈时,该模型有较高精度;并结合火蔓延的主要因素(气象因子、气候、地形等),进行系统分析,写出算地,编制实现地表火蔓延的预测预报计算机系统软件。这对于有效的组织扑救、减少火灾损失、计算森林火灾的损失评估有重要意义。  相似文献   

16.
Footedness is a personal quality like handedness. Footedness may be associated with moving ability during mounting, dismounting, and jumping movements. Occupational accidents have occurred during movement at different working levels, during the use of access and exit systems, and during the mounting of vehicles. Aging can also affect accident risk and body laterality. For example, falling accidents on stairs are common among the elderly. One reason for accidents may be that the structure of the access system or stair system is unsuitable for individual moving patterns depending partly on body laterality. Footedness and the way the feet are used may be contradictory to the demands of the moving situation, especially during uncommon or rapid situations. This contradiction may trigger disturbance during moving. The aims of this pilot study were (a) to review the literature briefly and (b) to describe the use of the dominant and nondominant foot by farmers and the elderly when mounting a tractor and stairs, respectively. The study also gives ideas for future studies based on both (a) and (b).  相似文献   

17.
为了减少滑坡造成的损失,提高滑坡预测的准确性,通过搭建灾害模拟平台获得滑坡的实验数据,在获得多组模拟实验数据后,分析各变量的特性。首先,通过层次分析(Analytic Hierarchy Process,AHP)算法,对滑坡进行危险度划分;然后,通过支持向量机(Support Vector Machine,SVM)建立模型,遗传算法(Genetic Algorithm,GA)再优化SVM参数,提出1种层次分析法与GA-SVM相耦合的模型。研究结果表明:AHP方法划分后的数据,通过GA与SVM结合建立的模型精度较好,实验预测结果与实际结果较为吻合,与单一SVM相比,精度更高,结果更好,更加适用于多变量的复杂非线性滑坡预警。  相似文献   

18.
Leadership theories have shifted over the last few decades from a focus on managerial functions and economic leader–follower exchanges toward greater focus on the interpersonal dynamics occurring within the leadership process. Theories such as transformational, ethical, authentic, and other “newer genre” theories were created to address neglected topics such as leader vision and inspirational messages, transparency, emotional effects, morality, individualized attention, and intellectual stimulation. Critiques of these theories, however, have been raised. In this paper, we address five of those critiques and argue for the validity and practical effectiveness of the new genre theories. Further, we describe how newer genre leadership research should be viewed as a performative epistemology, entailing a process of co‐creation involving scholars and practitioners. Finally, from this view, we provide general ideas for leader development. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

19.
Occupational Safety and Health in Finland   总被引:1,自引:0,他引:1  
In Finland, occupational safety is the responsibility of the employer, while the occupational safety and health laws are enforced by the Labour Inspection Service, an organization of the state. The Labour Inspection is divided in 11 administrative districts, and it employs 360 professionals. They are mandated to carry out site visits without prearranged appointments to inspect safe work situations, working hours, construction safety, or any aspect of accident risks. The inspectors are also mandated to verify the existence of sufficient occupational health services as prescribed by the Occupational Health Services Act for all employees. The occupational health services are typically provided by enterprise-owned medical departments, by mutually owned health care centers, by private practitioners, or by municipal health care centers. The latter are required by law to provide all services as prescribed by the legislation to anyone who comes to the facility. This situation is prevalent in the countryside, where there are very few private caregiving centers. Declaring occupational accidents and disease cases is mandatory, and the Inspection districts examine all accidents to establish causes and consequences, and to initiate prosecution in case of criminal negligence. Labour Inspection Districts are also notified of the new occupational disease cases as they are declared to insurance companies. Insurance for occupational disease, accidents, and death is an obligation of the employer, although they can choose the insurance company. The medical confidentiality between the workers and their occupational health care providers is very strict. Official statistics are maintained by the state Statistics Finland organization, and they may be used, for example, for research purposes by scientific institutes like the Finnish Institute of Occupational Health. Construction industry accounts for 25% of all fatal accidents (120 cases per 1 million working hours), followed by mechanical, wood, metal, machinery, and pulp and paper industry (10% each of fatal accidents) with rates ranging from 100–160 cases per 1 million working hours. There are some 5,000 occupational disease cases per year (rate 22/10,000 employed). The major disease categories include repetitive strain injuries (1,300 cases), respiratory allergies (600 cases), occupational skin diseases (1,000 cases), and 900 cases of noise-caused hearing loss. In 1998, 589 cases of asbestos-related diseases were reported.  相似文献   

20.
公路隧道火灾逃生疏散研究   总被引:2,自引:1,他引:1  
以苍岭隧道为背景,首先采用经验计算理论和计算软件building EXODUS相结合的方式,从被困人员的安全疏散时间、高温烟气的影响、隧道横通道的利用率以及人员的疏散行为特性进行了研究。结果表明:中小规模火灾情况下的安全疏散时间控制在8 min之内,高温烟气影响不大,但横通道的利用率不平均,且人员疏散路线相对集中。然后对存在的逃生疏散问题提出针对性建议以及其他相关建议,旨在为更大程度降低事故的严重性和经济财产损失。  相似文献   

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