A general stochastic clustering method for automatic cluster discovery

Finding clusters in data is a challenging problem. Given a dataset, we usually do not know the number of natural clusters hidden in the dataset. The problem is exacerbated when there is little or no additional information except the data itself. This paper proposes a general stochastic clustering method that is a simplification of nature-inspired ant-based clustering approach. It begins with a basic solution and then performs stochastic search to incrementally improve the solution until the underlying clusters emerge, resulting in automatic cluster discovery in datasets. This method differs from several recent methods in that it does not require users to input the number of clusters and it makes no explicit assumption about the underlying distribution of a dataset. Our experimental results show that the proposed method performs better than several existing methods in terms of clustering accuracy and efficiency in majority of the datasets used in this study. Our theoretical analysis shows that the proposed method has linear time and space complexities, and our empirical study shows that it can accurately and efficiently discover clusters in large datasets in which many existing methods fail to run.     

基于反馈控制的嵌入式实时系统调度算法设计

针对嵌入式实时系统在系统负载模型不确定的情况下系统的实时任务错过率过高以及调度稳定性差的问题,提出了一个基于反馈控制的调度模型.该模型主要由改进的多级队列调度器和3个控制器(准入控制器、执行等级控制器、比例积分微分(PID)控制器)组成.任务的错过率偏差反馈到PID控制器,产生相应的调整量并作用于其他两个控制器,对实时任务的执行等级进行调整, 经过调整的任务被调度器调度执行.在对模型中每个部件进行了一些结构调整和改进设计之后,将该调度模型应用于嵌入式可配置操作系统(eCos)中.实验结果表明,该模型降低了任务的时限错过率,同时解决了系统频频超载的问题.     

酮肼交联体系在阴极电泳涂料中的应用

使用苯乙烯、丙烯酸酯单体以及功能单体甲基丙烯酸缩水甘油醚(GMA)和交联单体双丙酮丙烯酰胺(DAAM)对中分子量的环氧树脂(E-20)进行接枝改性,并对改性的环氧树脂进行胺化、酸化、自乳化处理,从而制备出含有活性酮羰基的阳离子型乳液;以此乳液为基本成膜物质,选用己二酰肼(ADH)与体系中酮羰基进行交联,并进一步加入少量...     

响应面优化低糖滇红奶茶的配方

目的 通过响应面法优化低糖滇红奶茶的配方。方法 以滇红茶、全脂奶粉、零卡糖为主要原料,通过单因素分析结合响应面实验设计优化滇红奶茶配方,并分析产品的理化及卫生指标。结果 优化配方为：滇红茶汁50%、全脂奶粉15%、零卡糖10%、乳化剂0.22%、稳定剂0.2%,此时感官评分为87.83。滇红奶茶浅棕色稳定性好、质地均匀、浓稠恰当、细腻滑润无杂质,甜味适中茶香味与奶香香味协调无异味,经测定蛋白质含量(5.99±0.06)%、脂肪含量(3.38±0.02)%、茶多酚含量(320.6±2.25) mg/kg,微生物指标符合国家标准。结论 本研究开发了一种低糖健康的滇红奶茶,为滇红茶的深加工提供一定的实验依据。     

CH4在PVDF中渗透行为及机理的分子模拟研究

采用巨正则蒙特卡洛法(GCMC)和分子动力学法(MD)相结合的方法模拟研究了典型气体CH4在聚偏氟乙烯(PVDF)中的吸附扩散行为,探讨了温度及压力对气体吸附扩散能力的影响,分析了CH4在PVDF中的吸附位点及扩散轨迹.模拟结果表明,CH4在PVDF中的溶解系数、渗透系数随温度的升高先增大后减小,随压力的升高而增大;扩...     

基于摆度规律与CAD相结合的导瓦间隙分配算法研究及应用

导瓦间隙分配是水轮发电机组安装检修过程中一项十分重要的工作,合适的瓦间隙是机组健康运行的重要保障.针对瓦间隙计算存在的操作难度大、计算速度慢、精准度低等问题,建立了立式水轮发电机组盘车摆度模型,分析了其摆度特性,推导了实际最大净全摆度计算公式.通过分析瓦间隙计算公式的几何意义,提出了一种结合AutoCAD快速标注的瓦间...     

武钢2号高炉炉缸炉底维护

随着冶炼的强化、炉顶压力的提高和低硅生铁冶炼,武钢2号高炉炉缸、炉底侵蚀加快,为此采取一系列维护炉缸、炉底的措施,同时妥善处理了高炉稳定顺行与维护炉缸、炉底之间的矛盾,既抑制了高炉炉缸、炉底的进一步加剧,同时高炉各项技术经济指标大幅度改善.     

Highly efficient white organic light-emitting devices based on a multiple-emissive-layer structure

Characteristics of white organic light-emitting devices based on phosphor sensitized fluorescence are improved by using a multiple-emissive-layer structure, in which a phosphorescent blue emissive layer is sandwiched between red and green&yellow ones. In this device, bis[(4,6–difluorophenyl)–pyridinato–N,C²] (picolinato), bis(2,4–diphenyl–quinoline) iridium (III) acetylanetonate, fac tris (2-phenylpyridine) iridium, and 5,6,11,12–tetraphenylnaphthacene are used as blue, red, green, and yellow emitters, respectively. The device has a maximum luminance of more than 30,000 cd/m², a maximum luminous efficiency of 27 cd/A, a maximum external quantum efficiency of 12.4%, and a color rendering index of 81 at 100 cd/m².     

炸药小药卷性能的初步研究

试验得出了几种炸药在不同药卷直径下的性能结果，并２锥形装药测定了炸药的熄爆直径。论文安泡乳化炸药的小药卷最适用于煤矿井下岩巷掘进的全断面爆破作业。