ActiveSort: Efficient external sorting using active SSDs in the MapReduce framework

In the last decades, there has been an explosion in the volume of data to be processed by data-intensive computing applications. As a result, processing I/O operations efficiently has become an important challenge. SSDs (solid state drives) are an effective solution that not only improves the I/O throughput but also reduces the amount of I/O transfer by adopting the concept of active SSDs. Active SSDs offload a part of the data-processing tasks usually performed in the host to the SSD. Offloading data-processing tasks removes extra data transfer and improves the overall data processing performance.In this work, we propose ActiveSort, a novel mechanism to improve the external sorting algorithm using the concept of active SSDs. External sorting is used extensively in the data-intensive computing frameworks such as Hadoop. By performing merge operations on-the-fly within the SSD, ActiveSort reduces the amount of I/O transfer and improves the performance of external sorting in Hadoop. Our evaluation results on a real SSD platform indicate that the Hadoop applications using ActiveSort outperform the original Hadoop by up to 36.1%. ActiveSort reduces the amount of write by up to 40.4%, thereby improving the lifetime of the SSD.     

Highly selective sorting of semiconducting single wall carbon nanotubes exhibiting light emission at telecom wavelengths

Single wall carbon nanotubes (SWNTs) are known for their exceptional electronic properties.However,most of the synthesis methods lead to the production of a mixture of carbon nanotubes having different chiralities associated with metallic (m-SWNTs) and semiconducting (s-SWNTs) characteristics.For application purposes,effective methods for separating these species are highly desired.Here,we report a protocol for achieving a highly selective separation of s-SWNTs that exhibit a fundamental optical transition centered at 1,550 nm.We employ a polymer assisted sorting approach,and the influence of preparation methods on the optical and transport performances of the separated nanotubes is analyzed.As even traces of m-SWNTs can critically affect performances,we aim to produce samples that do not contain any detectable fraction of residual m-SWNTs.     

Application of image processing and radial basis neural network techniques for ore sorting and ore classification

Ore sorting is a useful tool to remove gangue material from the ore of bigger size ranges. The radical development in the area of artificial intelligence allows speedy processing the full color digital images for the preferred investigations. In this paper a novel approach to classify the ores for ferromanganese metallurgical plant feed has been proposed based on the visual texture of the ore particles (Mn, Fe, and Al₂O₃ rich) and radial basis neural network. The visual texture of ore particles vary with the mineral contents. This information can be quantified by using image processing technique in RGB color space and, first and second-order statistical analysis. Commonly used Hartlic’s textural features was calculated and presented as neural network inputs along with red, green and blue color values for 5 × 5 pixel size windowpanes extracted from three separate images. Results obtained show encouraging accuracy to apply the approach to develop an expert system for on line ore quality monitoring to control the ore blending in the feed ore circuits as well as separating gangue minerals present in the feed ores. Matlab^® 7.0 was used for visual textural analysis and neural network classification.     

龙岗区生活垃圾分类现状及对策研究

通过调查深圳龙岗现有城市生活垃圾分类现状和收运模式,分析其存在的问题和成因,提出深圳市龙岗区生活垃圾分类处理的策略。     

Identification,Isolation, and Characterization of Melanocyte Precursor Cells in the Human Limbal Stroma

Given their vital role in the homeostasis of the limbal stem cell niche, limbal melanocytes have emerged as promising candidates for tissue engineering applications. This study aimed to isolate and characterize a population of melanocyte precursors in the limbal stroma, compared with melanocytes originating from the limbal epithelium, using magnetic-activated cell sorting (MACS) with positive (CD117/c-Kit microbeads) or negative (CD326/EpCAM or anti-fibroblast microbeads) selection approaches. Both approaches enabled fast and easy isolation and cultivation of pure limbal epithelial and stromal melanocyte populations, which differed in phenotype and gene expression, but exhibited similar functional properties regarding proliferative potential, pigmentation, and support of clonal growth of limbal epithelial stem/progenitor cells (LEPCs). In both melanocyte populations, limbus-specific matrix (laminin 511-E8) and soluble factors (LEPC-derived conditioned medium) stimulated melanocyte adhesion, dendrite formation, melanogenesis, and expression of genes involved in UV protection and immune regulation. The findings provided not only a novel protocol for the enrichment of pure melanocyte populations from limbal tissue applying easy-to-use MACS technology, but also identified a population of stromal melanocyte precursors, which may serve as a reservoir for the replacement of damaged epithelial melanocytes and an alternative resource for tissue engineering applications.     

酒钢桦树沟铁矿石智能分选机预选抛废试验研究

采用X射线透射智能分选技术对酒钢桦树沟铁矿石进行预选抛废处理,结果表明,抛废率13％左右时,能够取得尾矿品位小于10％、铁回收率大于96％、预选粗精矿铁品位提高3.6个百分点以上的指标,试验结果稳定、数据可再现,说明利用该智能分选机可以实现酒钢镜铁山桦树沟铁矿石的有效预选抛废、提高铁矿石输出品位.     

FAULT-TOLERANT DESIGN OF BATCHER–BANYAN CLASS ATM SWITCHES

Many proposed packet switching systems for high-speed networks have employed the Batcher–banyan fabric due to its modular structure, self-routeing functionality, and distributed conflict-resolving mechanism. In this paper, we present a systematic fault-tolerant design for the Batcher–banyan class of switches. Our first concern is the development of an on-line error detection mechanism which is the prerequisite of any effective fault tolerant operation. Based on the technique developed by Davis, we propose a general fault-testing technique and verify it for a variety of unique-path self-routeing networks. Furthermore, we extend this method to Batcher sorting networks and construct a fault-tolerant Batcher sorter. Lastly, after contemplating the technique constraints and system performance, we deploy the above techniques into different levels of the Batcher–banyan networks and achieve a fault-tolerant version of the StarBurst switch, a member of the Batcher–banyan class of switches.     

基于SNORT的入侵规则动态排序方法研究

提出了一个实时的动态调整入侵规则的方法。该方法让入侵检测系统的规则在表头与功能选项的关联条件下,执行自动排序,使之能在一定的时间排序出最佳的规则读取顺序,以在最短的时间内检测出入侵行为,提升检测效能。实验证明该方法可行有效,具有较高的实用价值。     

基于CCD技术的生产线自动分选系统的研究

在CCD技术的基础上,根据生产线在线检测的原理及误差,提出了在线检测的机械传动系统和计算机控制系统,并对检测系统的光源、执行机构和控制元件等进行了分析研究。控制系统采用的串口通信是工业控制中常用的通信方式,运用VB. NET编写上位机程序,并利用SerialPort类实现与下位机进行串口通信。通过对光电开关和步进电机控制原理进行研究,设计出一种合适的光电开关接线电路以实现精确控制。将实验室样机试验中出现的问题进行了分析总结。     

基于PLC的具有分拣功能的自动化立体仓库设计

随着我国经济的高速发展,铁路、公路货物集散中心陆续出现,货物流通趋于小批量、多品种和准时制,各类配送存储中心的货物分拣任务十分艰巨。我国目前多数配送存储中心都是人工分拣,这种方式无法满足大规模存取配货的要求。而以往的自动化仓库中仅仅针对于一种货物的储存和管理,为此该文提出了一种具有自动分拣能力的自动化立体仓库的设计。系统中使用条码扫描装置来识别货物,整个操作过程可以通过触摸屏来控制,大大提高了系统的自动化水平。