基于连续小波和支持向量机分类音乐类型

音乐类型分类主要包括两个阶段:特征提取和分类.文中在研究小波变换理论基础上,采用连续小波分析方法提取音乐特征参数.支持向量机是专门针对有限样本情况下的一种分类方法.它是建立在统计学习理论的VC维理论和结构风险最小原理基础上,根据有限的样本信息在模型的复杂性和学习能力之间寻求最佳折衷,以期获得最好的推广能力.采用指数径向基函数(ERBF)内核,分类正确率可达85%,比传统的混合高斯模型和K近邻分类器,分类性能分别提高了21%和23%.实验结果表明,采用小波和支持向量机方法是一种相当有效的音乐类型分类方法.     

URBAN BUILT ENVIRONMENTS,ACCESSIBILITY, AND TRAVEL BEHAVIOR IN A DECLINING URBAN CORE: THE EXTREME CONDITIONS OF DISINVESTMENT AND SUBURBANIZATION IN THE DETROIT REGION

The research explores the impact of socioeconomic and racial variables on accessibility to urban amenities and travel in compact urban built environments that have traditionally been viewed as improving access to daily destinations and promoting nonmotorized travel: urban environments characterized by high densities, mixed land uses, and high connectivity. The study focuses on six neighborhoods in the Detroit region. Two neighborhoods are within the city itself, and predominantly poor and Black, and four of the neighborhoods are in the region surrounding the city, and they are predominantly wealthy and White. This study at the neighborhood scale enables an analysis into how class and race affect accessibility and travel in neighborhoods experiencing urban disinvestment and decline. The research shows that the traditional relationship between high densities, mixed land uses, high connectivity, greater accessibility, and pedestrian activity is significantly weaker in declining inner cities.     

Quantification of structural changes in acute inflammation by fractal dimension,angular second moment and correlation

The aim of the study was to examine alteration and possible application of fractal dimension, angular second moment, and correlation for quantification of structural changes in acutely inflamed tissue. Acute inflammation was induced by injection of turpentine oil into the right and left hind limb muscles of mice, whereas control animals received intramuscular saline injection. After 12 h, animals were anesthetised and treated muscles collected. The tissue was stained by hematoxylin and eosin, digital micrographs produced, enabling determination of fractal dimension of the cells, angular second moment and correlation of studied tissue. Histopathological analysis showed presence of inflammatory infiltrate and tissue damage in inflammatory group, whereas tissue structure in control group was preserved, devoid of inflammatory infiltrate. Fractal dimension of the cells, angular second moment and correlation of treated tissue in inflammatory group decreased in comparison to the control group. In this study, we were first to observe and report that fractal dimension of the cells, angular second moment, and correlation were reduced in acutely inflamed tissue, indicating loss of overall complexity of the cells in the tissue, the tissue uniformity and structure regularity. Fractal dimension, angular second moment and correlation could be useful methods for quantification of structural changes in acute inflammation.     

Time dependent upward frequency shifts in the Orbitron MASER

In our experiments with the pulsed Oribtron MASER, we have noted that there is an upward chirp in frequency even though the anode voltage is decreasing. We have found theoretically that this is a natural consequence of the negative-mass instability and the chirp rate can be predicted from this theory. Experimental data we have obtained is also in good agreement with these predictions.     

ETHNICITY IN AN IMMIGRANT GATEWAY CITY: THE ASIAN CONDITION IN HOUSTON

The analysis explores the evolving condition of Houston's Chinese community into the early 21st century and its uncertain role within the local economy. Through a historical analysis, it examines Chinese immigration into Houston and the evolving and changing spatial settlements of Chinese immigrants in the city, showing the precarious nature of Houston Chinese neighborhoods. A quantitative analysis then examines whether disparities in economic prosperity are evident between Asian and White growth neighborhoods within Harris County between 1980 and 2000, when ethnic diversity was viewed as an important element of Houston's new economic development strategy. A principal components analysis (PCA) and a k‐means clustering technique are conducted on census tract data to identify neighborhood types and to analyze changes in neighborhood characteristics. The quantitative analysis reveals that the city's promotion and celebration of ethnic diversity, and the extensive investment by Houston's Asians into their neighborhoods, did not translate into improving economic prospects for Asian neighborhoods within Houston.     

Photoelectric properties of MISM phthalocyanine structure

Langmuir-Blodgett films have been prepared from copper tetra-4-t-butylphthalocyanine. A voltage dependence of capacitance can be attributed to the presence of a Schottky depletion layer. The barrier potential was determined as l·4eV, and the carrier concentration about 10²⁴m^?3     

微生物对混凝土的侵蚀(英文)

微生物侵蚀会导致混凝土的严重破坏,尤其导致了城市污水收集和处理系统的过早破坏,使其需要提前修复。世界范围内的研究结果表明:处于污水和下水道污泥中的混凝土会遭受由硫酸盐、酸、CO2等导致的严重破坏。评述了混凝土处于利于细菌生长和生物降解环境中时的细菌、微生物侵蚀破坏过程。此外还分析了硫酸产生的机理(硫循环)、用于污水管道系统和农用工业的混凝土的受侵蚀破坏机理以及评价混凝土抵抗微生物侵蚀的方法。