A low leakage TG-CNTFET–based inexact full adder for low power image processing applications

This paper presents a highly stable, low leakage inexact full adder (FA) which is based on top gate carbon nanotube field effect transistors (TG-CNTFET) for motion detector applications. Inexact arithmetic circuits are highly accepted in low power multimedia applications. Circuit level metrics, ie, average power, propagation delay, power-delay product (PDP), and leakage power dissipation as well as application level metric such as peak signal to noise ratio (PSNR) are considered to compare the performance of proposed inexact FA. All the simulations are performed using HSPICE tool with Stanford 32-nm TG-CNTFET model. The operating frequency used for simulation is 1-Ghz with 0.9-V supply voltage. Proposed inexact FA successfully achieve manifold reduction in leakage power as well as consume 89.2% lesser energy as compared with latest existing inexact FA while having other parameters in acceptable range. Simulations using MATLAB show satisfactory image quality and PSNR value for motion detection applications. The effect of variations in voltage and temperature on leakage power is also presented which confirms stability of the proposed circuit.     

发展我国大型电网的自动发电控制模式

常规自动发电控制（ＡＧＣ／ＥＤ）因受其数学模型及算法本身的局限,难以解决诸如“ＬＦＣ－ＥＤ的协调”、“电网安全约束的考虑”、“电网分层控制体系结构下各级自动发电控制模式相适应”等问题,在我国大型电网中的应用受到极大限制。文章试图探讨改进常规ＡＧＣ／ＥＤ的数学模型及算法,探讨采用现代控制理论设计的ＡＧＣ／ＥＤ闭环控制系统的技术特点,提出改进和发展适合我国大型电网自动发电控制的模式。     

基于LabVIEW的数据采集系统在金属结合剂金刚石砂轮电火花整形上的应用

在本文中，使用霍尔电流电压传感器，数据采集卡，电容测微仪，基于LabVIEW编程语言建立了数据采集系统：通过数据采集系统实时监测金刚石砂轮电火花整形过程，以及测量砂轮圆度。揭示出电火花整形不同阶段电流电压变化的基本规律，而且通过电流和电压图形，可以判断出砂轮是否达到了某一电参数下的整形精度极限：实验结果表明最后整形阶段的微小进给量及低电压、低占空比和高频率的电参数对提高整形精度具有重要作用。基于LabVIEW的数据采集系统的电火花整形技术有助于提高精密整形的精度。W10金刚石砂轮最终可达到小于2μm砂轮圆跳.     

Effects of alginate oligosaccharide mixtures on the growth and fatty acid composition of the green alga Chlamydomonas reinhardtii

Alginate is a natural acidic linear polysaccharide that is produced by brown seaweeds. It is currently used in a broad range of commercial enterprises, such as the food and medical products industries. Recent evidence has demonstrated that alginate oligosaccharides may function as growth promoting agents for certain plant cells, including those of some green algae. Chlamydomonas reinhardtii is a green alga that is used as a model organism in fundamental molecular biology studies; it is also a producer of biohydrogen. In the present study, we examined effects of two types of alginate oligosaccharide mixtures (AOMs), which were prepared by either enzymatic degradation (ED) or acid hydrolysis (AH), on the growth of C. reinhardtii. Growth was significantly promoted by AOM (ED) in a concentration-dependent manner. The maximum effect was observed on day 4 of treatment. The fatty acid composition of C. reinhardtii was also influenced by AOM (ED); the levels of C16:0, C18:2 cis and C18:3 n-3 increased in treated cells. AOM (AH) and the other saccharides that we tested did not affect the growth of C. reinhardtii. The effects that we identified could promote efficient biomass production by reducing culture times and by changing cellular fatty acid levels.     

Aggregate Structures: Material and Machine Computation of Designed Granular Substances

In inanimate nature, large masses of granular substances are in constant processes of formation through perpetual cycles of erosion and accretion. What if architecture was to emulate this behaviour and allow for its own continuous reconfiguration? Karola Dierichs and Achim Menges establish the notion of an ‘aggregate architecture’. Composed of large numbers of unbound yet designed granules, aggregates are based on a fundamentally different logic of construction. In contrast to assembly systems, aggregates materially compute their overall constructional configuration and shape as spatiotemporal behavioural patterns, with an equal ability for both: the stable character of a solid material and the rapid reconfigurability of a fluid. Copyright © 2012 John Wiley & Sons, Ltd.     

镁合金微弧氧化电源驱动电路的可靠性分析

微弧氧化是一种新型的表面处理方法,利用该电路可输出双端不对称的高压脉冲,且脉冲幅值、频率、占空比均在一定范围内连续可调。本文首先介绍了微弧氧化电源技术的发展现状,然后对试验中使用过的几种IGBT驱动模块M57959、2ED300、2SD315 3种驱动电路的结构、工作原理和使用性能做了详细分析对比。实验表明,Eupec系列的2ED300驱动电路结构简单,可靠性高,适用于大功率微弧氧化电源的驱动。     

A NEW METHOD FOR MACHINING OF ELECTRICALLY NONCONDUCTIVE WORKPIECES USING ELECTRIC DISCHARGE MACHINING TECHNIQUE

In this study, a new method for machining of nonconductive ceramic workpieces in electric discharge machining (EDM) was developed. Machining surfaces of nonconductive workpieces were coated with a conductive layer (CL) and graphite powder was added to dielectric fluid for machining. Al₂O₃, ZrO₂, SiC, B₄C and glass workpiece samples were machined by using the method. Different machining conditions were tested for each sample and optimum machining parameters were determined. Effect of electrical conductivity, thermal conductivity and melting point of workpieces on material removal rate (MRR) was investigated. Optical microscope and SEM (Scanning Electron Microscope) surface photographs of workpieces taken after machining are presented and discussed.     

基于半定规划的{0,1}-经济调度

基于内点半定规划,提出一种直接求解{0,1}-经济调度问题({0,1}-ED)的新方法.通过引入辅助变量,该方法将原整数变量约束转化为凸二次约束,进而将{0,1}-ED问题转化为半定规划问题,并用内点法进行求解.对于大系统整数变量的微小偏差,应用简单的启发式技术调整.ED-420等9个测试系统的仿真结果表明,所提方法能够有效地处理{0,1}-经济调度,对于大多数问题都可以得到较精确的结果,计算时间具有多项式复杂性.     

三维母线槽计算机辅助设计系统

三维母线槽计算机设计系统综合利用了编译原理,计算机辅助几何造型技术和工程数据库技术,为母线槽设计提供了智能化、集成化、标准化的解决方案,文中对其基本结构、设计思想关键技术进行陈述,并给出了一设计实例。