West Middlands Mosses cSAC, Wybunbury Moss and Abbots Moss

This is the report on Habitats Directive, the Review of Consents Stage 1 and 2 by the Environment Agency of the West Midlands Mosses cSAC, Wybunbury Moss and Abbots Moss. The Habitats Directive has the main aim to promote the maintenance of biodiversity by defining a common framework for the conservation of wild plants and animals and habitats of community interest. The Directive establishes a European ecological network known as "Natura 2000". The network comprises Special Areas of Conservation (SAC) and Special Protection Areas (SPA). In the section on Stage 1 or Screening Process of the Habitat Directive, it is identified the likely impacts upon the West Midlands Mosses cSAC, Wybunbury Moss and Abbots Moss of a project, plan or activities, either alone or in combination with other projects, plans or activities, and considers whether these impacts are likely to be significant. In the section on Stage 2 or Appropiate Assessment of the Habitat Directive, it is considered the impact on the integrity of the West Midlands Mosses cSAC, Wybunbury Moss and Abbots Moss of the projects, plans or activities, either alone or in combination with other projects, plans or activities, with respect to the site’s structure and function and its conservation objectives. Additionally, where these are adverse impacts, an assessment of the potential mitigation of those impacts. The criteria used in this report to identify relevant projects, plans or activities and their impacts are water quality discharge consents, waste management licences, abstraction licences, Integration Pollution Control (IPC) and Integrated Pollution Prevention Control (IPPC) permits. Proformas, hydrogeological and GIS maps are included in the review.

Oak Mere cSAC

This is the report on Habitats Directive, the Review of Consents Stage 1 and 2 by the Environment Agency of the Oak Mere cSAC. The Habitats Directive has the main aim to promote the maintenance of biodiversity by defining a common framework for the conservation of wild plants and animals and habitats of community interest. The Directive establishes a European ecological network known as "Natura 2000". The network comprises Special Areas of Conservation (SAC) and Special Protection Areas (SPA). In the section on Stage 1 or Screening Process of the Habitat Directive, it is identified the likely impacts upon the Oak Mere cSAC of a project, plan or activities, either alone or in combination with other projects, plans or activities, and considers whether these impacts are likely to be significant. In the section on Stage 2 or Appropiate Assessment of the Habitat Directive, it is considered the impact on the integrity of the Oak Mere cSAC of the projects, plans or activities, either alone or in combination with other projects, plans or activities, with respect to the site’s structure and function and its conservation objectives. Additionally, where these are adverse impacts, an assessment of the potential mitigation of those impacts. The criteria used in this report to identify relevant projects, plans or activities and their impacts are water quality discharge consents, waste management licences, abstraction licences, Integration Pollution Control (IPC) and Integrated Pollution Prevention Control (IPPC) permits. Proformas, hydrogeological and GIS maps are included in the review.

Pulsewidth switchable, wavelength tuneable ultrafast fiber laser mode-locked by carbon nanotubes

Employing a nanotube-based saturable absorber, we demonstrate a continuously tunable (1533-1563nm) ultrafast fiber laser, with output pulsewidth switchable between picosecond (1.2 ps) and femtosecond (610 fs) regimes. © 2012 IEEE.

Ultrashort pulse generation in diode laser devices

The generation of ultrashort optical pulses by semiconductor lasers has been extensively studied for many years. A number of methods, including gain-/Q-switching and different types of mode locking, have been exploited for the generation of picosecond and sub-picosecond pulses [1]. However, the shortest pulses produced by diode lasers are still much longer and weaker than those that are generated by advanced mode-locked solid-state laser systems [2]. On the other hand, an interesting class of devices based on superradiant emission from multiple contact diode laser structures has also been recently reported [3]. Superradiance (SR) is a transient quantum optics phenomenon based on the cooperative radiative recombination of a large number of oscillators, including atoms, molecules, e-h pairs, etc. SR in semiconductors can be used for the study of fundamental properties of e-h ensembles such as photon-mediated pairing, non-equilibrium e-h condensation, BSC-like coherent states and related phenomena. Due to the intrinsic parameters of semiconductor media, SR emission typically results in the generation of a high-power optical pulse or pulse train, where the pulse duration can be much less than 1 ps, under optimised bias conditions. Advantages of this technique over mode locking in semiconductor laser structures include potentially shorter pulsewidths and much larger peak powers. Moreover, the pulse repetition rate of mode-locked pulses is fixed by the cavity round trip time, whereas the repetition rate of SR pulses is controlled by the current bias and can be varied over a wide range. © 2012 IEEE.

Dual-wavelength, carbon nanotube mode-locked fiber laser

We demonstrate a dual-wavelength, carbon nanotube mode-locked Er fiber laser. The laser outputs two wavelengths at 1549nm and 1562nm, and each wavelength corresponds to pulse duration of ∼1.3ps and repetition rate of ∼11.27MHz. © 2012 IEEE.

Characteristics and applications of InGaN micro-light emitting diodes on Si substrates

InGaN micro-light emitting diodes on Si substrates have been fabricated and characterized. Their abilities for micro-display, high modulation bandwidth of 270 MHz and data transmission rate of up to 400 Mbit/s have been demonstrated. © 2013 IEEE.

Precision transfer printing of ultra-thin AlInGaN micron-size light-emitting diodes

We report the fabrication of a mechanically-flexible 16×16 array of thin-film, micron-size LEDs emitting at 480 nm. Devices were transfer-printed onto a mechanically-flexible ITO backplane using a modified, high-precision (placement accuracy ±25 nm) assembly system. © 2013 IEEE.

一种可证明安全的消息认证码

消息认证码是保证消息完整性的重要工具,它广泛应用于各种安全系统中.随着可证明安全理论的逐渐成熟,具备可证明安全的消息认证码无疑成为人们的首选.本文基于XOR MAC和PMAC的构造方法,使用分组密码构造了一种确定性、可并行的消息认证码-DXOR MAC(Deterministic XOR MAC).在底层分组密码是伪随机置换的假设下,本文使用Game-Playing技术量化了攻击者成功伪造的概率,从而证明了其安全性.

一个改进的可动态调节的机密性策略模型

试图提出一个模型,它能为有效处理网络安全对象提供支持.改进Amon ott的动态调整规则,使需要动态改变的量减少,从而使一个系统调用级的原子操作需要伴随的附加量的操作和存储减少,提高模型在系统中的实用性.通过把当前安全级变成敏感标签范围而增加模型在系统实现中的灵活性,能有效控制IPC对象.为此,把Amon ott动态地调整当前敏感标签的规则推广为动态地调整敏感标签范围的规则,这把Bell为处理网络情况而把主体的当前安全级变成敏感标签范围的工作与Amon ott的工作有机地结合起来,同时,参考实际中使用的系统GEMSOS和DG/UX及安全原型微内核系统Fluke,引入了单级实体、多级实体以及专用于进程的访问模式,并给出了它们应满足的不变量及限制性条件.另外,在参考原型系统TMach对IPC对象的某些处理方式的基础上,提出了使动态特征非常明显的IPC对象得到合理、有效管理的机制,同时还分析了ABLP实施方法中存在的一些不当之处.提出了一个新的机密性策略模型DBLP的模型不变量,限制性条件及变量类型和常量,并分析了一些限制性条件的合理性,它可以有效应用于系统设计。

真空机械手控制方法研究

集束型制造设备已经成为半导体生产半导体行业中的主流制造设备。在集束型制造设备中，一台真空机械手负责在不同的制造工序即各制造腔体间搬运晶圆，作用不可或缺。目前真空机械手由200mm晶圆规格向300mm晶圆规格发展，国外进行技术封锁，我国真空机械手相关研究严重滞后。本文以科技部“超大规模集成电路制造装备重大专项”为依托进行了真空机械手控制方法的研究。 本文分析了真空机械手需要解决的关键问题，在研究各种先进控制方法的基础上，对于真空机械手建模、控制器结构、运动学控制方法、动力学控制方法和轨迹规划方法进行了系统研究，主要贡献有： 1)．为实现机械手的实时控制，求解了真空机械手的运动学正反解，解决了反解中的多解取舍问题。采用拉格朗日方法建立了真空机械手并联手臂中串联支链的动力学方程。由于并联手臂中驱动和非驱动关节的混合使用，采用拉格朗日-达朗贝尔方法建立了并联真空机械手的动力学模型，为实现真空机械手的高精度快速控制作了充分的准备。 2)．针对真空机械手控制器的特殊性，研究开放式控制器结构的设计方案。采用PMAC运动控制板构建真空机械手控制器，为开放式模块化真空机械手控制器的实现奠定了基础。针对真空机械手工作的特性，提出集束型设备中传输模组控制器结构，并按照其具体工作顺序，对真空机械手动作指令进行了设计。以上工作为控制算法的实现提供了良好的平台。 3)．对于直接驱动的电机伺服控制问题，提出了IP位置控制来保证电机的良好伺服性能；针对PMSM的建模误差和非线性扰动以及负载扰动提出采用H∞负载扰动观测器对扰动及电机模型变化进行补偿；针对单个电机独立控制时无法对机械强耦合进行有效控制的问题，提出了基于并联方式的双电机3环(位置、速度和加速度) H∞同步控制方法，能够较好地解决机械手并联手臂在运行中发生扭转的问题。通过仿真实验验证了所提出的方法。 4)．电机伺服控制中考虑了双电机的同步问题，但是手臂机械耦合的哥氏力及离心力等因素仅仅是作为电机轴上的扰动来处理。为了进一步提高控制精度和稳定性，提出了针对机械手动力学模型的控制方法。首先采用PD计算力矩控制；为了消除计算力矩控制无法解决的有扰动和模型不准确时的静差问题，提出了模糊补偿的计算力矩控制方法。但该方法仅仅是缓解了而不能完全解决这一问题，因此，在控制器内引入积分项以消除静差。同时，为了提高系统动态响应性能，使用模糊逻辑来调节控制器的各个参数。仿真实验表明了所提出方法的有效性。 5)．在分析各种轨迹规划方法的基础上，结合真空机械手运行中的实际要求提出了真空机械手时间最优轨迹规划方法。使机械手末端能够运行于允许的最大加减速度，并且保证运动的平稳性。推导了动力学方程在笛卡尔空间的表示形式，建立起了关节电机力矩与末端运行的位置、速度和加速度的关系，分析了轨迹规划中加速度规划的变化对关节电机的影响，为选择电机和减小关节机械部件冲击提供了理论依据。给出了所提出规划方法的仿真实验结果，并与关节空间进行的梯形轨迹规划做了对比，证明了本文提出的方法能够有效缩短运行时间，以及满足末端加速度约束。最后，对于本文提出的轨迹规划方法在真空机械手样机上做了实验，并与笛卡尔空间的梯形规划方法的实验结果做了对比，证明所提出的方法能够满足真空机械手运行时兼顾效率与稳定性的要求。

多轴伺服控制器在自动化装备中的应用

在对自动化装备技术改造的过程中,需要用“电子齿轮多轴交流伺服系统”来取代使用效果欠佳的机械齿轮系统.介绍了交流伺服传动技术在某大型卷接机组中应用的总体设计方案,详细论述了该系统的工作原理,阐述了工控机、DSP、PLC及多轴伺服控制器在该装备中的综合运用.并以安川多轴伺服控制器为例,详细介绍了该装备中引入多轴伺服控制器的硬件、软件设计.实际应用表明,该设计是成功的,各项性能指标均优于原来的机械装置,能够有效降低噪音,减少能耗.

Declarative Transport: No More Transport Protocols to Design, Only Policies to Specify

Transport protocols are an integral part of the inter-process communication (IPC) service used by application processes to communicate over the network infrastructure. With almost 30 years of research on transport, one would have hoped that we have a good handle on the problem. Unfortunately, that is not true. As the Internet continues to grow, new network technologies and new applications continue to emerge putting transport protocols in a never-ending flux as they are continuously adapted for these new environments. In this work, we propose a clean-slate transport architecture that renders all possible transport solutions as simply combinations of policies instantiated on a single common structure. We identify a minimal set of mechanisms that once instantiated with the appropriate policies allows any transport solution to be realized. Given our proposed architecture, we contend that there are no more transport protocols to design—only policies to specify. We implement our transport architecture in a declarative language, Network Datalog (NDlog), making the specification of different transport policies easy, compact, reusable, dynamically configurable and potentially verifiable. In NDlog, transport state is represented as database relations, state is updated/queried using database operations, and transport policies are specified using declarative rules. We identify limitations with NDlog that could potentially threaten the correctness of our specification. We propose several language extensions to NDlog that would significantly improve the programmability of transport policies.

Assessing the Security of a Clean-Slate Internet Architecture

The TCP/IP architecture was originally designed without taking security measures into consideration. Over the years, it has been subjected to many attacks, which has led to many patches to counter them. Our investigations into the fundamental principles of networking have shown that carefully following an abstract model of Interprocess Communication (IPC) addresses many problems [1]. Guided by this IPC principle, we designed a clean-slate Recursive INternet Architecture (RINA) [2]. In this paper, we show how, without the aid of cryptographic techniques, the bare-bones architecture of RINA can resist most of the security attacks faced by TCP/IP. We also show how hard it is for an intruder to compromise RINA. Then, we show how RINA inherently supports security policies in a more manageable, on-demand basis, in contrast to the rigid, piecemeal approach of TCP/IP.

Review of methods to predict solder joint reliability under thermo-mechanical cycling

Solder joints are often the cause of failure in electronic devices, failing due to cyclic creep induced ductile fatigue. This paper will review the modelling methods available to predict the lifetime of SnPb and SnAgCu solder joints under thermo-mechanical cycling conditions such as power cycling, accelerated thermal cycling and isothermal testing, the methods do not apply to other damage mechanisms such as vibration or drop-testing. Analytical methods such as recommended by the IPC are covered, which are simple to use but limited in capability. Finite element modelling methods are reviewed, along with the necessary constitutive laws and fatigue laws for solder, these offer the most accurate predictions at the current time. Research on state-of-the-art damage mechanics methods is also presented, although these have not undergone enough experimental validation to be recommended at present