Design and testing of an ortho-planar micro-valve

This paper presents the production and testing of an ortho-planar one-way micro-valve. The main advantages of such valves are that they are very compact and can be made from a single flat piece of material. A previous paper presents and discusses a micro-valve assembly based on a spider spring. The present paper focuses on the valve assembly process and the valve performance.. Several prototypes with a bore of 0.2 mm have been built using two manufacturing techniques (μEDM and stereo-lithography) and tested for pressures up to 7 bars. © 2008 International Federation for Information Processing.

Modelling and characterisation of an ortho-planar micro-valve

The main difficulties encountered in the development of microscale fluidic pumping systems stem from the fact that these systems tend to comprise highly three-dimensional parts, which are incompatible with traditional microproduction technologies. Regardless of the type of pumping principle, most of the hydraulic systems contain valves and in particular a one-way valve. This paper presents the design and modelling of an ortho-planar one-way microvalve. The main advantages of such a valve are that it is very compact and can be made from a single flat piece of material. An analytical model of the spring deflection has been developed and compared to FEM. A prototype with a bore of 1.5 mm has been build using a micro EDM (electro discharge machining) machine and also tested. © 2006 International Federation for Information Processing.

M-type channels selectively control bursting in rat dopaminergic neurons

Midbrain dopaminergic neurons in the substantia nigra, pars compacta and ventral tegmental area are critically important in many physiological functions. These neurons exhibit firing patterns that include tonic slow pacemaking, irregular firing and bursting, and the amount of dopamine that is present in the synaptic cleft is much increased during bursting. The mechanisms responsible for the switch between these spiking patterns remain unclear. Using both in-vivo recordings combined with microiontophoretic or intraperitoneal drug applications and in-vitro experiments, we have found that M-type channels, which are present in midbrain dopaminergic cells, modulate the firing during bursting without affecting the background low-frequency pacemaker firing. Thus, a selective blocker of these channels, 10,10-bis(4-pyridinylmethyl)-9(10H)- anthracenone dihydrochloride, specifically potentiated burst firing. Computer modeling of the dopamine neuron confirmed the possibility of a differential influence of M-type channels on excitability during various firing patterns. Therefore, these channels may provide a novel target for the treatment of dopamine-related diseases, including Parkinson's disease and drug addiction. Moreover, our results demonstrate that the influence of M-type channels on the excitability of these slow pacemaker neurons is conditional upon their firing pattern. © 2010 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

pkn22 (alr2502) encoding a putative Ser/Thr kinase in the cyanobacterium Anabaena sp PCC 7120 is induced by both iron starvation and oxidative stress and regulates the expression of isiA

In cyanobacteria, the isiA gene is required for cell adaptation to oxidative damage caused by the absence of iron. We show here that a putative Ser/Thr kinase gene, pkn22 (alr2052), is activated by iron deficiency and oxidative damage in Anabaena sp. PCC 7120. A pkn22 insertion mutant is unable to grow when iron is limiting. pkn22 regulates the expression of isiA (encoding CP43') but not of isiB (encoding flavodoxin) and psbC (CP43). Fluorescence measurement at 77 K reveals the absence of the typical signature of CP43' associated with photosystem I in the mutant under iron-limiting conditions. We propose that Pkn22 is required for the function of isiA/CP43' and constitutes a regulatory element necessary for stress response. (C) 2003 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

A TPR-family membrane protein gene is required for light-activated heterotrophic growth of the cyanobacterium Synechocystis sp PCC 6803

The unicellular cyanobacterium Synechocystis sp. PCC6803 can grow heterotrophically in complete darkness, given that a brief period of illumination is supplemented every day (light-activated heterotrophic growth, LAHG), or under very weak ( < 0.5 mumol m(-2) s(-1)) but continuous light. By random insertion of the genome with an antibiotic resistance cassette, mutants defective in LAHG were generated. In two identical mutants, sll0886, a tetratricopeptide repeat (TPR)-family membrane protein gene, was disrupted. Targeted insertion of sll0886 and three downstream genes showed that the phenotype was not due to a polar effect. The sll0886 mutant shows normal photoheterotrophic growth when the light intensity is at 2.5 mumol m(-2) s(-1) or above, but no growth at 0.5 mumol m(-2) s(-1). Homologs to sll0886 are also present in cyanobacteria that are not known of LAHG. sll0886 and homologs may be involved in controlling different physiological processes that respond to light of low fluence. (C) 2003 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.

方差阴影图中的光渗现象消除算法

方差阴影图算法使用概率的方法计算像素被遮挡的上限概率,通过对深度图滤波的方法来有效地减少阴影图算法中的走样问题,但在深度比较复杂的场景中方差阴影图算法会出现光渗现象,即在应该是阴影的区域却有了亮度.文中使用最小-最大阴影图来辅助消除方差阴影图中的光渗现象,在对深度纹理进行滤波的同时生成一个最小-最大阴影图;在实时绘制场景时,利用最小-最大阴影图来辅助判断当前片元是否完全处在阴影区域内部,由此生成更真实、更准确的阴影.该算法可以很容易地添加到已有的方差阴影图算法的片元处理程序中,并且不会对原有阴影的柔和边界以及绘制的帧率产生影响.

一种改进的自适应逃逸微粒群算法及实验分析

分析了变异操作对微粒群算法（panicle swarm optimization，简称PSO）的影响，针对收敛速度慢、容易陷入局部极小等缺点，结合生物界中物种发现生存密度过大时会自动分家迁移的习性，给出了一种自适应逃逸微粒群算法，并证明了它依概率收敛到全局最优解．算法中的逃逸行为是一种简化的确定变异操作．当微粒飞行速度过小时，通过逃逸运动使微粒能够有效地进行全局和局部搜索，减弱了随机变异操作带来的不稳定性、典型复杂函数优化的仿真结果表明，该算法不仅具有更快的收敛速度，而且能更有效地进行全局搜索．

专家群体思维收敛的研究

讨论一个复杂的决策问题 ,专家群体决策是解决这类问题的一种有效方法 .当专家群体研讨形成了一些定性的方案之后 ,用群体一致性算法 ,使专家群体的思维逐渐趋于收敛 ,最终达到群体意见一致 .在上述过程中主持人的作用非常重要 ,他引导专家群体达成一致 ,提高了群体决策的效率 .专家群体思维收敛的整个过程体现了人机结合的思想 ,充分发挥了人和计算机各自的优势 ,共同来解决复杂的问题 .

用综合集成方法解决企业决策问题

介绍了从定性到定量的综合集成以及从定性到定量的综合集成研讨厅体系情况 .提出用综合集成思想来解决企业决策问题 ,并给出企业决策研讨厅体系的框架结构 .将 ARIS集成到研讨厅中 ,以辅助领导者做决策 .用 ARIS对某大型企业建立动态模型 ,在不同初始条件下进行仿真 ,分析仿真结果 ,决策者还可根据经验、信息不断修改仿真条件或模型 ,最终可得出较好的、可行的经营模式 .将解决复杂问题的方法用于企业的经营管理活动中 ,可以帮助企业更好地解决重大或日常决策问题 .

基于多笔交互的儿童讲故事系统

单显示多输入的交互方式具有节约设备成本和提高合作效率的优点,如何实现多个输入设备独立地控制是其中的关键问题。针对此问题,提出了多笔交互技术,从设备层开始分离各笔设备的输入,为各笔构建单独的处理部分,实现多用户共享单显示设备的功能,并以笔式输入模式使得交互更加自然与高效。将多笔交互技术应用在儿童讲故事原型系统中,儿童可以共同进行故事创作。结果表明,多笔交互技术能使多个儿童同时操作,共享讲故事软件,带给儿童新的协作体验。

群体一致性及其在研讨厅中的应用

提出了一种群体一致性算法。讨论了在群体专家进行决策的过程中 ,当专家研讨形成了一些方案时 ,用群体一致性算法 ,使专家群体思维不断趋于收敛 ,并最终达到群体意见一致 ,得出各方案的排序及决策结果。在上述过程中主持人的作用非常重要 ,他引导专家群体达成一致 ,提高了群体决策的效率。针对宏观经济决策问题 ,提出了一种宏观经济研讨的近拟方法。在综合集成研讨厅体系中 ,使用群体一致性算法 ,以解决研讨厅中的专家群体思维的收敛问题。

基于形象化标签推荐技术的聋儿康复资源系统

针对目前教育、教学资源系统中存在的问题,在以用户为中心的场景设计方法指导下,提出了简单、易学、易用和高效4个层次递进的系统设计开发目标,并重点分析研究了Web2.0的个性化服务:标签和推荐服务。结合这两种服务的优势,在提出和实现形象化标签推荐技术后,阐述了其设计与实现。结合聋儿康复资源系统的设计与开发,详细地介绍了整个系统的功能框架、实现流程以及形象化标签在系统中的运用。最后对全文进行了总结,并对下一步研究工作做出了展望。

基于上下文的多通道语义融合

多通道交互已经成为人机交互领域一个重要的研究方向,对多通道输入的信息进行语义融合是其中的关键问题。提出了一种将上下文与传统语义融合相结合的方法,并将这一方法应用在面向儿童使用的讲故事原型系统中。儿童通过受限的自然语言、笔的勾画等方式进行故事创作。结果表明,笔和语音结合的多通道交互方式能够使得儿童更方便、自然地与计算机进行交互,结合上下文的语义融合方法能够在一定程度上修正输入错误。

虚拟企业协同中的标准化研究

虚拟企业是企业适应环境变化的必然结果,体现了企业的适应性。文章介绍了标准和标准化工作的相关概念。通过分析虚拟企业运作中存在的问题,指出标准化对虚拟企业的运作有着至关重要的作用,并探讨了业务流程的标准化问题对企业间协同的影响。

维护开发中敏捷方法的应用

该文主要介绍了敏捷软件开发的几种主要方法以及在维护性开发中的实际应用，并与传统重型开发法进行了对比，表明敏捷软件开发方法在软件开发中的一些先进之处及存在的一些问题；同时介绍了软件的维护及维护性开发的重要意义，在此基础上提出将敏捷方法用于软件的维护性开发中，对该应用的可行性和具体的实现过程给出了分析，并给出开发过程的实例说明，证明了该方法的有效性，说明敏捷方法在软件维护性开发中的应用具有非常强的实际应用研究价值。