A machine cell formation algorithm for simultaneously minimising machine workload imbalances and inter-cell part movements

This paper considers a multi-objective machine cell problem, in which part types have several alternative part routings and the expected annual demand of each part type is known. This problem is characterised as optimally determining part type (routing) sets and corresponding machine cells such that total inter-cell part movements and total machine workload imbalances are simultaneously minimised. Due to the complexity of the problem, a two-stage heuristic algorithm is proposed, and computational experiments were conducted to verify the performance of the algorithm.     

一分二十微带Wilkinson功分器的设计

介绍了一种工作在S频段,一分二十的威尔金森功率分配器的设计方法,20个输出端口为1:1的等功率分配,系统阻抗为50 Ω。使用软件Advanced Design System 2009进行仿真,在2.17~2.20 GHz的工作频率内,表现出良好的电气性能,输入端口反射系数在-18 dB,该功分器的20个输出端口的相位和幅度具有良好的一致性,端口幅度平衡度为±0.3 dB,相位平衡度±2°,输出端口的隔离度在-25 dB以下。     

The parallel ‘Deutschland-Modell’ - A message-passing version for distributed memory computers

The parallel ‘Deutschland-Modell’ and its implementation on distributed memory parallel computers using the message-passing library PARMACS 6.0 is described. Performance results on a Cray T3D are given and the problem of dynamical load imbalances is addressed.     

某百万∏型二次再热锅炉再热器壁温偏差调整

某百万双切圆∏型二次再热锅炉试运过程中高/低压末级再热器壁温沿炉宽方向存在壁温偏差大的问题,限制两级再热汽温达到设计值。通过烟气再循环喷口反切和燃尽风喷口反切,减小了高/低压末级再热器的壁温偏差,为两级再热汽温达到设计值打下了基础。     

Growth and physiological responses of Black Spruce (Picea mariana) to sites dominated byLedum groenlandicum

Growth and physiological parameters of black spruce planted eight years previously were compared at sites with and withoutLedum groenlandicum to quantify the adverse effects on black spruce inLedum sites. Tree height, crown diameter, and dry weights of stems, branches, and needles of black spruce were significantly less at theLedum-dominated sites. Annual stem height, basal diameter, growth ring width, and cumulative wood volume of black spruce were significantly reduced in theLedum sites compared to those of the non-Ledum sites. Yearly growth of black spruce in the first seven years after planting was more affected in theLedum site than the eighth year's growth. Foliar nutrient analysis of black spruce in theLedum site showed an overall imbalance in nutrient accumulation. Black spruce growing in theLedum site had higher foliar concentrations of Al, Ca, Fe, Ni, and S and lower concentrations of N and Si than those growing in the non-Ledum site. Black spruce growing in theLedum site also had a higher foliar phenolic content. Preliminary experiments suggest thatLedum has the potential to leach water-soluble phenolics to its immediate organic soil.     

和差幅相不平衡校正与角误差数字化处理

分析了导致和差支路幅相不平衡的原因及幅相不平衡对测角精度的影响。并提供了一种和差支路幅相不平衡数字校正和角误差归一化处理的方法。     

Rapid transaction to load variations of active filter supplied by PV system

This paper deals with the analysis and control of a photovoltaic (PV) system connected to the main supply through a Boost converter and shunt active filter supplied by a PV system providing continuous supply of nonlinear load in variation. A robust control of a PV system connected to the grid while feeding a variable nonlinear load is developed and highlighted. This development is based on the control of the Boost converter to extract the maximum power from the PV system using the Perturb and Observe (P and O) algorithm in the presence of temperature and illumination. The proposed modeling and control strategy provide power to the variable nonlinear load and facilitates the transfer of power from solar panel to the grid while improving the quality of energy (harmonic currents compensation, power factor compensation and dc bus voltage regulation). Validation of the developed model and control strategy is conducted using power system simulator Sim-Power System Blockset Matlab/Simulink. To demonstrate the effectiveness of the shunt active filter to load changes, the method of instantaneous power (pq theory) is used to identify harmonic currents. The obtained results show an accurate extraction of harmonic currents and perfect compensation of both reactive power and harmonic currents with a lower THD and in accordance with the IEEE-519 standard.     

Interactive Relationships between Intestinal Flora and Bile Acids

The digestive tract is replete with complex and diverse microbial communities that are important for the regulation of multiple pathophysiological processes in humans and animals, particularly those involved in the maintenance of intestinal homeostasis, immunity, inflammation, and tumorigenesis. The diversity of bile acids is a result of the joint efforts of host and intestinal microflora. There is a bidirectional relationship between the microbial community of the intestinal tract and bile acids in that, while the microbial flora tightly modulates the metabolism and synthesis of bile acids, the bile acid pool and composition affect the diversity and the homeostasis of the intestinal flora. Homeostatic imbalances of bile acid and intestinal flora systems may lead to the development of a variety of diseases, such as inflammatory bowel disease (IBD), colorectal cancer (CRC), hepatocellular carcinoma (HCC), type 2 diabetes (T2DM), and polycystic ovary syndrome (PCOS). The interactions between bile acids and intestinal flora may be (in)directly involved in the pathogenesis of these diseases.     

基于级联模型的输变电设备状态图像分类方法

对采集到的输变电设备状态图像进行智能化分析是一种实时有效的设备状态监测方式。传统机器学习算法在处理电力设备图像分类问题时,由于不考虑代价敏感和类别不平衡问题,效率较低。文中针对输变电设备状态图像的特点,提出一种基于级联模型的图像分类方法,并通过实验验证该方法的优越性。     

稀疏多径信道环境中MIMO-OFDM系统的IQ不平衡和信道联合估计

该文针对稀疏多径信道环境中的MIMO-OFDM系统所存在的IQ不平衡问题,提出了一种IQ不平衡参数和信道的联合估计方法.推导了联合估计的时域模型,提出了基于l1-l2优化模型和平行坐标下降算法的联合估计算法.仿真结果表明,所提方法与传统的频域最小二乘算法和匹配追踪算法相比,显著提高了系统性能.