Sensitivity analysis of nonlinear fractional order control systems with state delay

In this paper, we consider a class of nonlinear fractional order control system with delay in state variable. Existence and uniqueness of solution are shown by using method of steps. The sensitivity of the state and control with respect to the parameters of the system is shown. Finally, analytical results are substantiated by numerical examples.     

ILB®, a Low Molecular Weight Dextran Sulphate,Restores Glutamate Homeostasis,Amino Acid Metabolism and Neurocognitive Functions in a Rat Model of Severe Traumatic Brain Injury

In a previous study, we found that administration of ILB^®, a new low molecular weight dextran sulphate, significantly improved mitochondrial functions and energy metabolism, as well as decreased oxidative/nitrosative stress, of brain tissue of rats exposed to severe traumatic brain injury (sTBI), induced by the closed-head weight-drop model of diffused TBI. Using aliquots of deproteinized brain tissue of the same animals of this former study, we here determined the concentrations of 24 amino acids of control rats, untreated sTBI rats (sacrificed at 2 and 7 days post-injury) and sTBI rats receiving a subcutaneous ILB^® administration (at the dose levels of 1, 5 and 15 mg/kg b.w.) 30 min post-impact (sacrificed at 2 and 7 days post-injury). Additionally, in a different set of experiments, new groups of control rats, untreated sTBI rats and ILB^®-treated rats (administered 30 min after sTBI at the dose levels of 1 or 5 mg/kg b.w.) were studied for their neurocognitive functions (anxiety, locomotor capacities, short- and long-term memory) at 7 days after the induction of sTBI. Compared to untreated sTBI animals, ILB^® significantly decreased whole brain glutamate (normalizing the glutamate/glutamine ratio), glycine, serine and γ-aminobutyric acid. Furthermore, ILB^® administration restored arginine metabolism (preventing nitrosative stress), levels of amino acids involved in methylation reactions (methionine, L-cystathionine, S-adenosylhomocysteine), and N-acetylaspartate homeostasis. The macroscopic evidences of the beneficial effects on brain metabolism induced by ILB^® were the relevant improvement in neurocognitive functions of the group of animals treated with ILB^® 5 mg/kg b.w., compared to the marked cognitive decline measured in untreated sTBI animals. These results demonstrate that ILB^® administration 30 min after sTBI prevents glutamate excitotoxicity and normalizes levels of amino acids involved in crucial brain metabolic functions. The ameliorations of amino acid metabolism, mitochondrial functions and energy metabolism in ILB^®-treated rats exposed to sTBI produced significant improvement in neurocognitive functions, reinforcing the concept that ILB^® is a new effective therapeutic tool for the treatment of sTBI, worth being tested in the clinical setting.     

MODELING SIMULATION AND CONTROL OF THE WOOD DRYING PROCESS Part 1. A Set of PDE's as an Internal Model

Abstract

The internal model proposed is a nonlinear system of a few partial differential equations. The boundary conditions for the differential equations are specified at the lumber board entrance and between the wood and air. The initial conditions are calibrated by solving the static model and by the technical experiment. In conclusion, it can be said that the consistency of the model with experimental results seems to be reasonably good and can be used for process simulation and control     

Security optimal power flow considering loading margin stability using hybrid FFA–PS assisted with brainstorming rules

This paper presents a new power system planning strategy which combines firefly algorithm (FFA) with pattern search algorithm (PS). The purpose is minimizing total fuel cost, total power loss and reducing total voltage deviation, with the objective of enhancing the loading margin stability and consequently the power system security. A new interactive and simple mechanism, inspired in brainstorming process, is proposed that allows FFA and PS algorithms to explore new regions of the search space. In this study the Static VAR compensator (SVC) is modeled and integrated in an efficient location which is chosen considering the voltage stability index. The proposed algorithm is interactive and tries to optimize a set of control variables at the same time, namely, active power generations, voltage of generators, tap transformers, and the reactive power of shunt compensators to optimize three objective functions such as: fuel cost, total power loss and total voltage deviation. These variables are optimized using a flexible interactive and competitive search mechanism. The proposed planning strategy has been examined and applied to two practical test systems IEEE 14-Bus and IEEE 30-Bus. Simulation results confirm the effectiveness of this hybrid strategy for solving the security optimal power flow.     

加权随机减量法

随机减量方法是70年代初提出的一种获取线性振动系统自由响应的技术.这种方法对于施加在线性系统上的随机激励只有定性的要求,而没有定量的要求.本文在传统的算术平均的随机减量法的基础上,提出了加权相加时移信号段的加权随机减量法,作了初步的理论论证,并通过数值仿真计算,证实了若选择合适的权函数,加权随机减量法能比原来的方法有更高的精度.文中也指出了算术平均法是本文加权随机减量法的一利特例.     

Fading Margin Analysis for Asynchronous CDMA Systems

In this paper, a detailed theoretical analysis of fading margin in an asynchronous code division multiple access (A-CDMA) system is discussed. Rayleigh and Rician frequency-selective slowly fading channels are considered. Probability distribution and density functions of the probability of error are derived for Rayleigh and Rician fading channels. The fluctuations in the channel capacity are proved to be directly proportional to the signal-to-noise ratio (SNR) variations. Fading margin is calculated for both Rayleigh and Rician fading channels as a function of the probability of error specification and the probability of unsatisfactory operation.     

频谱校正中利用卷积运算构造新窗函数的研究

给出并理论证明,运用卷积运算构造的窗函数具有更加优良的性能;对这种方法所生成的新的窗函数的特性进行了理论分析,证明了其合理性;立足于现有频谱分析方法论证了这种方法的可行性;旨在为寻求品质更加优良的窗函数提供理论指导。     

自动铺带轨迹规划中测地线算法研究

本文针对复合材料自动铺放轨迹规划中自然路径求解中的测地线问题给出了求解两点之间的测地线的数值计算方法。该方法将微分方程的边值问题转化为初值问题,在初始方向的选取上较以往方法几何意义更为直观,算例证明算法的正确性。     

西宁特钢连铸机技术改造

对西钢新建生产线五机五流小方坯连铸机改造进行了综述.连铸机优良的装备为整条生产线向品种化、规模化、高效化方向快速发展奠定了基础.