Generalizing intersection kernel support vector machines for color texture based recognition

This paper presents a novel recognition approach in which the component-adaptive color co-occurrence matrices (CACCMs) are designed to characterize color and texture cues in the images, while histogram intersection kernel support vector machines (HIKSVMs) are generalized to the version compatible to color co-occurrence matrix (CCM), called CCM intersection kernel support vector machines (CIKSVMs). An ensemble learning framework is proposed for synchronously training the optimal marginal CIKSVMs and corresponding CACCMs’ extractors. This learning architecture is applicable to an arbitrary color space employed for image coding, while we pay utmost attention to a perceptual uniform color space for the prominent potential in image proprieties’ display. For the formulation of recognition algorithm, the set of multi-channel CACCMs (CAMCMs) of per sample is utilized to get a balance between discriminative power and computational efficiency, while multiple marginal CIKSVMs are combined by weighted majority voting. The effectiveness of our approach is validated by promising results obtained from four experimental datasets.     

Chitin and chitosan in selected biomedical applications

Chitin (CT), the well-known natural biopolymer and chitosan (CS) (bio-based or “artificial polymer”) are non-toxic, biodegradable and biocompatible in nature. The advantages of these biomaterials are such that, they can be easily processed into different forms such as membranes, sponges, gels, scaffolds, microparticles, nanoparticles and nanofibers for a variety of biomedical applications such as drug delivery, gene therapy, tissue engineering and wound healing. Present review focuses on the diverse applications of CT and CS membranes and scaffolds for drug delivery, tissue engineering and targeted regenerative medicine. The chitinous scaffolds of marine sponges’ origin are discussed here for the first time. These CT based scaffolds obtained from Porifera possess remarkable and unique properties such as hydration, interconnected channels and diverse structural architecture. This review will provide a brief overview of CT and CS membranes and scaffolds toward different kinds of delivery applications such as anticancer drug delivery, osteogenic drug delivery, and growth factor delivery, because of their inimitable release behavior, degradation profile, mucoadhesive nature, etc. The review also provides an overview of the key features of CT and CS membranes and scaffolds such as their biodegradability, cytocompatibility and mechanical properties toward applications in tissue engineering and wound healing.     

单级反激式PFC连续模式下电流有效值计算

单级反激式连续工作模式下功率因数校正电路的输入电压在半个工频周期内呈正弦变化。变压器绕组中的电流是一系列梯形脉冲,并且脉冲宽度以及电流的变化率都随着输入电压的瞬时值变化。依据有效值定义推导出了变压器原副边电流有效值的解析解;在相同的假设条件下,利用积分得出了电流有效值数值计算公式。解析解和数值解分析对比结果表明,两种计算结果具有很好的一致性。通过实验验证,用这种方法设计的变压器在同样温升的前提下,变压器体积大大减小。     

单级功率因数校正变换器的拓扑研究

简单介绍了国内外的单级功率因数校正变换器电路。对其主要电路拓扑进行了适当分类。同时提出一种新型的单级AC/DC 变换器电路,并对电路的工作原理进行了分析和实验研究,得到了较为满意的实验结果。     

基于C^＊Core的动态内存分配方案与实现

为了解决基于C＊Core系列芯片嵌入式开发过程中,C＊Core系统在某些情况下由于受操作系统、数据格式差异等因素影响,不能动态分配C＊Core系列芯片内存的问题,采用数组与标志位相结合的方法,提出一种C＊Core系列芯片在所有情况下都通用的动态内存分配方案。该方案利用C＊Core C语言编写实现,程序在苏州国芯公司CS32XDV10开发板上运行后,成功实现了动态分配CCM3118芯片内存功能。     

LED灯峰值恒流控制的方法

分析了LED灯的工作特点。为了提高整个LED驱动器的可靠性,对Buck电路峰值电流控制进行了分析。详细介绍了数字峰值电流CCM情况下的后缘调制原理,理论推导出电感电流在此工作情况下的Buck电路占空比的数学公式,仿真分析了后缘调制下的开关管的PWM波形及LED灯的电流波形。仿真分析可知,该调制下的LED灯电流波形输出恒定,纹波小。最后通过实验验证了LED灯恒流控制方法的可行性和可靠性。     

武钢第二炼钢厂连铸机改造方案及其工艺分析

介绍了武钢第二炼钢厂连铸机改造方案 ,并分析了现有连铸机的工艺缺陷以及本次改造拟将采用的技术措施 ,比较了直弧形连铸机与全弧形连铸机以及多点弯矫与连续弯矫方式的不同特点 ,同时 ,对武钢二炼钢厂连铸机系统下一步改造工作提出了建议。     

现场总线在连铸机改造中的应用

文中对马鞍山三钢厂１＃连铸机及其工艺作了简单介绍；重点论述了现场总线网络的组成及优点；概括地介绍了系统硬件、软件。本文是对现场总线运用的实践总结，有工程实际指导意义。     

结晶器在线热调宽液压伺服系统仿真与试验研究

本文对板坯连铸机结晶器在线热调宽装置进行受力分析,采用HyPneu仿真软件建立了该调宽装置的液压伺服控制模型,并对该模型进行了仿真分析及现场试验,验证了调宽装置液压系统设计的正确性及控制模型参数设置的合理性,同时证明了该软件具有较高的工程使用价值。     

直驱型风电系统大容量Boost PFC拓扑及控制方法

直驱型风力发电系统因其在风力机和发电机之间省去了增速装置,从而提高了系统的效率和可靠性,降低了系统维护费用和直接成本,并以其良好的低电压适应能力而受到越来越广泛的关注.然而,传统直驱系统采用三相不可控整流桥与带有大容量电容器的电压源电流控制型逆变器并网发电.这种结构向永磁同步发电机中注入了大量低频谐波,增加了系统损耗,进而减少了系统功率容量.针对其中的大容量Boost环节,提出一种将三个三相单管Boost型PFC电路并联,并采用载波相移技术加以控制的方案.仿真结果表明,在支路电流均工作于DCM模式的情况下,合成电流近似工作于CCM模式.实现了对永磁同步发电机的输出进行功率因数校正、降低发电机电流的谐波含量、改善永磁同步发电机的谐波特性、提高发电机有功功率输出能力和系统效率的目标.