基于坐标变换的微网功率解耦及限幅控制策略

传统的功率下垂控制在低压微电网中的直接应用会引起有功和无功功率的耦合问题,为此采用了基于坐标变换的虚拟功率下垂控制方法,并对其解耦特性、功率均分及限幅问题进行了研究.利用相对增益分析方法分析了采用坐标变换后系统功率的耦合程度,从理论上证明了当坐标变换矩阵与线路阻抗的阻感比相同时,虚拟功率下垂控制可以实现功率的完全解耦.针对线路阻抗差异而导致的功率无法均分问题,提出了通过增加虚拟负阻抗来实现并联逆变器间功率均分的方法.考虑到现有的虚拟功率下垂限幅范围与实际功率限幅范围的不对等性,提出了新型虚拟功率下垂限幅控制方法,将功率越限部分划分为8个区域,根据逆变器输出的实际功率确定其所属区域,进而采取相应的限幅调整措施.仿真结果验证了所提控制策略的正确性和有效性.     

一种基于VLAN技术的蜜网设计与实现

传统的网络安全措施都是被动型的防御技术,蜜罐及蜜网是网络安全领域中一个全新的概念,它是基于主动型的防御技术．本文在分析传统蜜罐和第二代蜜网技术基础上,建立数学模型,然后引入数据控制功能,提出了一种以VLAN三层交换技术为基础的新的蜜网组建方法．它不受物理位置的限制,组网灵活方便,不仅节省投资,而且提高了网络安全系数．     

消除我国数字鸿沟

针对我国数字鸿沟的现状,从基础设施、教育和技术等方面分析了我国数字鸿沟的消除。     

我国个人消费信贷问题分析与对策思索

文章在对我国个人消费信贷发展现状作了简单概括的基础上，着重从个人消费信贷利益双方——消费者和银行的角度，对制约我国个人消费信贷发展的需求约束和供给约束两方面作了相应分析和探讨，并就问题对策，略陈一得之见。     

高新技术产品的认定方法——指标约束法

针对国内外现行的高新技术产品确认方法不能满足我国高新技术产业发展需要的问题，根据我国高新技术产品确认工作的实际，设计出一种新的高新技术产品确认方法--指标约束法，以实现高新技术产品确认工作科学化和规范化。     

Obtaining Profiles Based on Localized Non-negative Matrix Factorization

Nonnegative matrix factorization (NMF) is a method to get parts based features of information and form the typical profiles. But the basis vectors NMF gets are not orthogonal so that parts-based features of information are usually redundancy. In this paper, we propose two different approaches based on localized non negative matrix factorization (LNMF) to obtain the typical user session profiles and typical semantic profiles of junk mails, The LNMF get basis vectors as orthogonal as possible so that it can get accurate profiles. The experiments show that the approach based on LNMF can obtain better profiles than the approach based on NMF.     

Comparison between Minimax and GLS Estimators in Linear Regression Model with Ellipsoid Restrictions

对于线性回归模型Ｙ＝Ｘβ＋ε,ε～（０,σ２Ｗ）,其中σ２＞０,Ｗ为正定矩阵．当未知参数β受到椭球约束时,文中分别在矩阵均方误和加权均方误意义下比较了β的Ｍｉｎｉｍａｘ估计（ＭＩＬＥ）与广义最小二乘估计（ＧＬＳＥ）之差异,并分别导出了在此两种意义下ＭＩＬＥ优于ＧＬＳＥ的充分必要条件．     

Protein profiling of 3T3-L1 adipocyte differentiation and (tumor necrosis factor α-mediated) starvation

The increased incidence of obesity and related disorders in Western societies requires a thorough understanding of the adipogenic process. Data at the protein level of this process are scarce. Therefore we performed a proteome analysis of differentiating and starving 3T3-L1 cells using two-dimensional gel electrophoresis combined with mass spectrometry. Effects of different starvation conditions were examined by subjecting 3T3-L1 adipocytes to caloric restriction, either in the absence or the presence of the lipolysis inducer tumor necrosis factor-. Ninety-three differentially expressed proteins were found during differentiation and starvation of 3T3-L1 cells, 50 of which were identified. GenMAPP/MAPP-finder software revealed a non-reciprocal regulation of the glycolytic pathway during 3T3-L1 differentiation followed by starvation. Furthermore, proteins involved in growth regulation, cytoskeletal rearrangements and protein modification, 16 of which have not been described before in 3T3-L1 cells, were identified. In conclusion, our data provide valuable information for further understanding of the adipogenic process.Received 9 November 2004; received after revision 21 December 2004; accepted 28 December 2004     

一种有限空间区域的机群调度优化算法

 基于有限空间区域调度优化问题,针对机群调度具体问题,先将机群保障流程整体抽象建模,再把物理模型转化为典型调度问题模型,设计启发式规则提出优化算法。算法分为上、下两层次,上层负责在有限区域内选择合适的停机位和起飞位,下层负责对单机各作业进行调度,下层把调度结果返回给上层算法,上层根据该调度结果自适应调节某架机的停机位和起飞位,重新调用下层算法以验证该调整是否能改善解的质量。以典型出动任务作为输入算例,求解出有限空间区域的机群调度方案结果。相比之前人工排布的方式,本方法在求解时间和结果优劣两方面更具优越性,该方法使得机群调度指挥方式向智能自动化过渡,对提升机群出动架次率有重要意义。