六角形蜂窝网络的反馈数

一个图的反馈点集指的是在去掉时导致图无圈的节点子集.反馈集问题来源于组合电路设计,在操作系统死锁预防,人工智能的贝叶斯推断、网络理论有大量应用.六角形蜂窝网络是一种新近提出的并行计算互连网络.本文通过构造的方法求出了蜂窝网格和蜂窝圆环面网络的反馈数.     

Effects of climate change on biomass production and substitution in north-central Sweden

In this study we estimate the effects of climate change on forest production in north-central Sweden, as well as the potential climate change mitigation feedback effects of the resulting increased carbon stock and forest product use. Our results show that an average regional temperature rise of 4 °C over the next 100 years may increase annual forest production by 33% and potential annual harvest by 32%, compared to a reference case without climate change. This increased biomass production, if used to substitute fossil fuels and energy-intensive materials, can result in a significant net carbon emission reduction. We find that carbon stock in forest biomass, forest soils, and wood products also increase, but this effect is less significant than biomass substitution. A total net reduction in carbon emissions of up to 104 Tg of carbon can occur over 100 years, depending on harvest level and reference fossil fuel.     

基于国密CPU卡的门禁管理系统设计

本文以国密算法CPU卡为核心，详细阐述了基于国密CPU卡的门禁管理系统的设计，并以佛山市文化中心为例，分析了国密CPU卡门禁在项目中的应用情况。     

Consideration of the use of autonomous,non-recallable unmanned vehicles and programs as a deterrent or threat by state actors and others

This paper considers the use of a non-recallable control technology (either for craft control or to command weaponized software) as a deterrent or threat mechanism by state and non-state actors. It considers the efficacy of this approach in modern war fighting (including in limited war-like scenarios), comparing it to the mutual assured destruction phenomenon created by atomic weaponry and the Zanryū Nipponhei (‘Japanese holdout’) scenario. The deterrent, immediate and long-term impacts of the non-recallable control technology are considered from a warfighting perspective. The ethical and societal implications of the development of this technology and the proverbial opening of Pandora's Box that its development represents are also considered.     

基于PWM整流器的电梯能量回馈系统的研究

充分利用再生能源是实现绿色节能电梯的有效技术之一。本文阐述了电梯能馈系统控制平台的构成原理、三相电压型PWM整流器的数学模型、双闭环控制结构和空间矢量算法及其实现,利用MATLAB的SIMULINK工具箱搭建了电梯双PWM变频器的计算机仿真模型,并对能馈系统的工作特性进行了仿真分析。结果表明:系统无论工作在整流还是逆变的情况下,都能保持直流母线电压的稳定,同时可以达到较高的功率因数,实现了能量的双向流动。     

Discrete‐time Lyapunov stable‐staggered estimator MIMO adaptive interference cancelation with experimental verification

Adaptive interference cancelation is of vital importance in a broad array of scientific and engineering disciplines. In this paper we develop a closed‐loop discrete‐time interference cancelation algorithm. The novel features of this algorithm are its ability to deal with multiple channels being affected by interferences with different frequency spectrums. Also we provide a proof of Lyapunov stability of closed‐loop system and asymptotically perfect interference cancelation for a class of interference signals. Furthermore, we introduce a new approach for updating the estimator through the use of staggered estimate. The goal of staggered estimation is to minimize the total number of estimates/calculations done within a time period while ensuring that there is no estimator aliasing. Finally, the proposed algorithm is implemented on an TMS320C6713 DSP Kit and an experimental verification is obtained. Copyright © 2009 John Wiley & Sons, Ltd.     

SINAMICS G120／PM250再生回馈型变频器在游梁式抽油机上的应用

本文主要介绍了西门子新一代再生能量回馈型变频器G120-PM250功率模块在游梁式抽油机上的成功应用，实现了游梁式抽油机运行时再生回馈电能的高效运行，达到了节能降耗和提高混油产量之目的。     

Individual and situational factors that influence the efficacy of personalized feedback substance use interventions for mandated college students.

Little is known about individual and situational factors that moderate the efficacy of personalized feedback interventions (PFIs). Mandated college students (N = 348) were randomly assigned either to a PFI delivered in the context of a brief motivational interview (BMI; n = 180) or to a written PFI only (WF) condition and were followed up at 4 months and 15 months postintervention. The authors empirically identified heterogeneous subgroups utilizing mixture modeling analysis based on heavy episodic drinking and alcohol-related problems. The 4 identified groups were dichotomized into an improved group (53.4%) and a nonimproved group (46.6%). Logistic regression results indicated that the BMI was no more efficacious than the WF across all mandated students. However, mandated students who experienced a serious incident requiring medical or police attention and those with higher levels of alcohol-related problems at baseline benefited more from the BMI than from the WF. It may be an efficacious and cost-effective approach to provide a written PFI for low-risk mandated students and an enhanced PFI with a BMI for those students who experience a serious incident or have higher baseline alcohol-related problems. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Adaptive robust output‐feedback motion control of hydraulic actuators

Most previous advanced motion control of hydraulic actuators used full‐state feedback control techniques. However, in many cases, only position feedback is available, and thus, there are imperious demands for output‐feedback control for hydraulic systems. This paper firstly transforms a hydraulic model into an output feedback–dependent form. Thus, the K‐filter can be employed, which provides exponentially convergent estimates of the unmeasured states. Furthermore, this observer has an extended filter structure so that online parameter adaptation can be utilized. In addition, it is a well‐known fact that any realistic model of a hydraulic system suffers from significant extent of uncertain nonlinearities and parametric uncertainties. This paper constructs an adaptive robust controller with backstepping techniques, which is able to take into account not only the effect of parameter variations coming from various hydraulic parameters but also the effect of hard‐to‐model nonlinearities such as uncompensated friction forces, modeling errors, and external disturbances. Moreover, estimation errors that come from initial state estimates and uncompensated disturbances are dealt with via certain robust feedback at each step of the adaptive robust backstepping design. After that, a detailed stability analysis for the output‐feedback closed‐loop system is scrupulously checked, which shows that all states are bounded and that the controller achieves a guaranteed transient performance and final tracking accuracy in general and asymptotic output tracking in the presence of parametric uncertainties only. Extensive experimental results are obtained for a hydraulic actuator system and verify the high‐performance nature of the proposed output‐feedback control strategy.     

An econometric analysis of the effects of the penalty points system driver's license in Spain

This article seeks to quantify the effects of the penalty points system driver's license during the 18-month period following its coming into force. This is achieved by means of univariate and multivariate unobserved component models set up in a state space framework estimated using maximum likelihood. A detailed intervention analysis is carried out in order to test for the effects and their duration of the introduction of the penalty points system driver's license in Spain. Other variables, mainly indicators of the level of economic activity in Spain, are also considered. Among the main effects, we can mention an average reduction of almost 12.6% in the number of deaths in highway accidents. It would take at least 2 years for that effect to disappear. For the rest of the safety indicator variables (vehicle occupants injured in highway accidents and vehicle occupants injured in accidents built-up areas) the effects disappeared 1 year after the law coming into force.