Security applications of computer vision

In an age which bears witness to a proliferation of Closed Circuit Television (CCTV) cameras for security and surveillance monitoring, the use of image processing and computer vision techniques which were provided as top end bespoke solutions can now be realised using desktop PC processing. Commercial Video Motion Detection (VMD) and Intelligent Scene Monitoring (ISM) systems are becoming increasingly sophisticated, aided, in no small way, by a technology transfer from previously exclusively military research sectors. Image processing is traditionally concerned with pre-processing operations such as Fourier filtering, edge detection and morphological operations. Computer vision extends the image processing paradigm to include understanding of scene content, tracking and object classification. Examples of computer vision applications include Automatic Number Plate Recognition (ANPR), people and vehicle tracking, crowd analysis and model based vision. Often image processing and computer vision techniques are developed with highly specific applications in mind and the goal of a more global understanding computer vision system remains, at least for now, outside the bounds of present technology. This paper will review some of the most recent developments in computer vision and image processing for challenging outdoor perimeter security applications. It also describes the efforts of development teams to integrate some of these advanced ideas into coherent prototype development systems     

Achieving security in integrated circuit card applications realityor desire?

It has always been claimed that smart cards provide a really high level of security, considering them as a tamper-proof device, with the possibility to auto-block some or all of the services it provides. Unfortunately, nowadays some hackers appear to have demonstrated the lack of security involved in some applications where Integrated Circuit Cards (ICC) have been used. This has led to the opinion that smart cards are not secure enough, and their security is only in the minds of the commercial companies involved with the technology. In this paper, the author explains the reasons why this hacking has succeeded. For example, sometimes memory cards have been used instead of smart cards, or very old smart cards have been issued and not renewed, or the development team involved has not used basic security techniques, such as diversified keys. The author also gives clues to achieve a high level of security depending on the final application, and the environment in which it is going to be used     

嵌入式实时操作系统中的安全性考虑

在综合化航空电子系统中,嵌入式实时操作系统已被广泛采用,而操作系统保证应用软件的安全性,则是目前要解决的首要问题。对照国内外在高安全性、强实时系统上的先进技术和先进经验,本文着重讨论了嵌入式实时操作系统中解决数据安全性的几点考虑,主要集中介绍了软件的分层防御体系、分区管理和信息安全管理技术、分区间通讯的“虚通道”技术等,以确保综合化航电系统的信息及数据安全的机密性和完整性,达到主动防御的能力。     

Recent advances in film cooling enhancement: A review

Film cooling is an indispensable scheme in the design of highly-efficient cooling configurations to satisfy the thermal protection requirement of turbine hot section components. During the last few decades, vast efforts have been paid on the discrete-hole film cooling enhancement. In this paper, some of the recent literatures related to the passive strategies (such as shaped film cooling holes, upstream ramps, shallow trenches, mesh-fed slots) and the active strategies (such as the use of pulsation modulating device or plasma actuator) for film cooling enhancement are surveyed, with the aim at presenting an updated overview about the state of the art in advanced film cooling. In addition, some challenging issues are also outlined to motivate further investigations in such a broad topic.     

承载紧固孔边应力强度因子

 <正> 1.孔边穿透裂纹应力强度因子 采用宽度修正系数FB(c/W),可得紧固件孔边裂纹的SIF式中f_1(α/R)、钉载作用时的FB(c/W)以及未开裂应力σ_Y(X)。对双向载荷下的宽度修正系数,采用文献的数据最小二乘拟合,得     

计算机信息安全评估标准

介绍了信息安全评估标准的发展过程以及TCSEC、CC等具有较大影响的安全评估标准,并对各个标准的特点及应用方式加以分析。最后,对信息安全评估标准未来的发展方向提出了自己的看法。     

MHD Waves and Heating in Coronal Holes

Coronal holes have been identified as source regions of the fast solar wind, and MHD wave activity has been detected in coronal holes by remote sensing, and in situ in fast solar wind streams. I review some of the most suggestive wave observations, and discuss the theoretical aspects of MHD wave heating and solar wind acceleration in coronal holes. I review the results of single fluid 2.5D MHD, as well as multi-fluid 2.5D MHD models of waves in coronal holes, the heating, and the acceleration of the solar wind be these waves.     

Review of research on low-profile vortex generators to control boundary-layer separation

An in-depth review of boundary-layer flow-separation control by a passive method using low-profile vortex generators is presented. The generators are defined as those with a device height between 10% and 50% of the boundary-layer thickness. Key results are presented for several research efforts, all of which were performed within the past decade and a half where the majority of these works emphasize experimentation with some recent efforts on numerical simulations. Topics of discussion consist of both basic fluid dynamics and applied aerodynamics research. The fluid dynamics research includes comparative studies on separation control effectiveness as well as device-induced vortex characterization and correlation. The comparative studies cover the controlling of low-speed separated flows in adverse pressure gradient and supersonic shock-induced separation. The aerodynamics research includes several applications for aircraft performance enhancement and covers a wide range of speeds. Significant performance improvements are achieved through increased lift and/or reduced drag for various airfoils—low-Reynolds number, high-lift, and transonic—as well as highly swept wings. Performance enhancements for non-airfoil applications include aircraft interior noise reduction, inlet flow distortion alleviation inside compact ducts, and a more efficient overwing fairing. The low-profile vortex generators are best for being applied to applications where flow-separation locations are relatively fixed and the generators can be placed reasonably close upstream of the separation. Using the approach of minimal near-wall protuberances through substantially reduced device height, these devices can produce streamwise vortices just strong enough to overcome the separation without unnecessarily persisting within the boundary layer once the flow-control objective is achieved. Practical advantages of low-profile vortex generators, such as their inherent simplicity and low device drag, are demonstrated to be critically important for many applications as well.     

Civil Access to NAVSTAR GPS

US government policy is established and procedures are being formulated to direct the implementation of techniques providing limited civil access to full GPS accuracy. The results of these efforts balance the conflicting needs of civil GPS navigation and positioning against national security requirements. Granting this access will require sufficient and demonstrable user need, must clearly provide for both national and security interests, and may lead to the imposition of a user service charge. This access will only apply to Precise Positioning Service configured, code-tracking GPS receivers.     

多排钉金属连接接头有限元分析方法研究

解决飞机结构中接头的应力集中问题是延长飞机结构寿命的关键。采用有限元方法对多钉结构的金属连接件的载荷分配进行了研究,并对铆接接头的细节进行应力分析,给出了接头各细节处的应力分布,从而确定了各铆钉孔边危险点处的应力集中系数。同时探讨了台阶形搭接接头的几何构形对铆钉传递载荷和钉孔边危险点处应力集中系数的影响,对其部分几何构形参数进行了优化设计,得到有效降低孔边应力的构形方案。该方案对接头结构的疲劳性能分析具有一定的参考价值。     

Charging the new batteries-IC controllers track new technologies

Demands for portability have fueled significant developments in new battery technology. These developments have resulted in many more options in selecting the battery type for use in a particular project, but since most applications today are opting for rechargeable battery systems, the availability of battery charging solutions can become an equally important criteria in the selection process. Complicating this process are the demands for fast-but safe-charging with charge algorithms easily implemented with low-cost hardware. With the higher levels of complexity attendant with these more demanding algorithms, solutions have come primarily from the integrated circuit industry and the purpose of this paper is to provide a few examples of the latest efforts in this arena, specifically as addressed to lead-acid, nickel metal-hydride, and lithium-ion technologies     

Coronal disturbances and their terrestrial effects

Coronal disturbances lead to geomagnetic storms, proton showers, auroras and a wide variety of other phenomena at Earth. Yet, attempts to link interplanetary and terrestrial phenomena to specific varieties of coronal disturbances have achieved only limited success. Here, several recent approaches to prediction of interplanetary consequences of coronal disturbances are reviewed. The relationships of shocks and energetic particles to coronal transients, of proton events to γ-ray bursts, of proton events to microwave bursts, of geomagnetic storms to filament eruptions and of solar wind speed increases to the flare site magnetic field direction are explored. A new phenomenon, transient coronal holes, is discussed. These voids in the corona appear astride the long decay enhancements (LDE's) of 2–50 Å X-ray emission that follow Hα filament eruptions. The transient holes are similar to long-lived coronal holes, which are the sources of high speed solar wind streams. There is some evidence that transient coronal holes are associated with transient solar wind speed increases.     

Large Capacity Magnetic Bubble Memories for Government Applications

Magnetic bubble memories are an all solid-state, nonvolatile technology that offers a viable alternative to rotating electromechanical memory systems. Rotating memory systems such as magnetic disks, tapes, or drums are often not practical in government applications because of maintenance, reliability, and security problems. Bubble memories offer improvements in the required system reliability for these applications and lend themselves to a modular memory design not possible with mechanical systems. A 244 Mbit memory system is described which is general purpose in design, has a block random access architecture, and has demonstrated its high reliability.     

复合材料层合板开口补强技术试验研究

国内外学者对复合材料开口非对称补强做了很多研究,但主要集中在小开口的插层补强及共固化补强上。对用机械连接补强技术和插层补强技术补强后的层合板,进行拉伸和剪切试验;并采用有限元方法对补强后的复合材料层合板进行数值仿真,仿真结果与试验结果吻合得较好。经试验研究和数值仿真,得到各补强方案在各工况下的最大应变位置,并将不同补强方案进行对比。结果表明:插层补强方案优于机械补强方案。     

镍基单晶合金气冷叶片模拟试样的蠕变性能研究

对带孔和不带孔的某第二代镍基单晶合金平板试样进行了蠕变性能试验研究与有限元对比计算.高温蠕变试验表明, 平板试样的晶体取向和是否开孔对蠕变寿命有明显的影响.气膜孔导致蠕变寿命的降低, 对[001]取向的影响大于[111]取向.在高温低应力条件下, [001]取向的蠕变性能要优于[111]取向.有限元分析结果表明, 气膜孔改变了试样中的应力分布, 在孔附近产生了高应力, 导致模拟试验蠕变寿命的降低.有限元计算蠕变持久寿命与试验结果吻合, 说明采用基于分切应力的蠕变持久寿命计算模型是合理的.      

Development of a TPS reuse library using COTS tools

In the past, functional test requirements (FTR) or test requirement documents (TRD) and test program sets (TPS) were standalone items developed by individual engineers. In some cases, one engineer would write the FTR/TRD and another would develop the TPS. Commercial ATLAS FTRs are prepared in ARINC 616 and 626 ATLAS. Military TRDs are written in IEEE ATLAS 716 versions. Previous test reuse attempts have not been successful because additional software, like browsers, is required to support these efforts. It was difficult to justify writing new software; for example, browsers to manage the application software. Today, commercial-off-the-shelf (COTS) tools are in place to browse and view information from circuit diagrams to documents to source code. These tools can develop hierarchies to organize the information. These COTS tools are available throughout Boeing on many types of workstations and personal computers on every engineer's desk. This paper discusses how a reusable test library (RTL) is being developed using commercial-off-the-shelf (COTS) tools, such as Mosaic, to address commercial and military test applications. It describes each of the tools and the process to develop TPSs using the reuse library. It defines the metrics and benefits achieved     

Potential defense applications of expert systems

The authors provide an overview of expert systems and how they may effect the development of future defense applications. Military uses of computers are outlined, and expert-systems fundamentals are described. Artificial research and development efforts by the military are examined, and potential military applications are discussed. Expert systems efforts at NASA, by the US Air Force, and for the Strategic Defence Initiative are considered     

气膜孔形状对排孔下游换热的影响

实验研究了气膜孔几何形状、二次流雷诺数及吹风比对孔排下游的局部换热系数的影响。所用孔形是簸箕形孔、圆锥形孔及圆柱形孔;实验的参数范围为二次流孔径雷诺数Re=10000～25000,二次流吹风比M=0.3～2.0,在上述范围选取了26个工况分别对3种孔形进行了实验。      

E-mail的安全问题与保护措施

全面分析了E -mail的安全问题 ,并提出了应该采用的有效方法 ,以保护E -mail系统能安全运行。     

冲击加多斜孔双层壁对流与冲击换热优化研究

对冲击加多斜孔双层壁孔内对流和冲击换热这两部分冷却达到最大进行了优化.冲击加多斜孔双层壁结构中单位面积冲击孔数量和多斜孔数量比为1∶3, 多斜孔倾角为30°.本优化属于混合约束优化, 采用序列无约束极小化方法进行优化.通过计算分析, 得出了在冲击加多斜孔双层壁在压力降和单位面积冷却气量一定条件下的优化结果, 存在冲击换热和多斜孔内换热的最佳分配, 该结果对指导冲击加多斜孔双层壁设计有指导意义.