半湿润雨养农业区冬小麦冠层反射光谱与长势的相关性分析

本文研究了黄土高原半湿润代表区甘肃省庆阳市西峰区冬小麦主要生育期（返青-抽穗）冠层反射光谱与反映长势的指标覆盖度及叶面积指数间的关系。结果表明,冬小麦覆盖度及叶面积指数同450nm、550nm、650nm、1　650nm波段反射率呈负相关关系,同850nm波段反射率呈正相关关系。起身前,冬小麦长势指标覆盖度及叶面积指数同各波段反射率相关关系大多不显著。起身以后,冬小麦覆盖度和叶面积指数与各波段反射率呈极显著相关关系。另外,为了更好的监测冬小麦长势,研究了8个常用的植被指数同冬小麦长势间的相关关系,这8个植被指数在起身后同冬小麦覆盖度及叶面积指数间存在着极显著的相关关系。并且,利用这8个植被指数建立了冬小麦长势线性及非线性回归监测模型,其中,线性模型能更好的监测冬小麦覆盖度,指数模型能更好的监测冬小麦叶面积指数,但不同的植被指数,拟合程度不同,其中,尤以NDVI拟合程度最高。     

中亚地区1982年至2002年植被指数与气温和降水的相关性分析

本文利用1982年～2002年间AVHRR-NDVI数据和气候研究组(CRU)降水与气温数据,分析了中亚5国21年来NDVI年际与季节变化特征及其与气候因子的相关关系.结果表明:①在植被生长季,53%地区NDVI年变化率＜±0.0005NDVI/a(无变化),40%地区NDVI年变化率＞0.0005 NDVI/a(增加),6%地区NDVI年变化率＜-0.0005 NDVI/a(下降):按照植被覆盖类型,除常绿林、高山草甸年均NDVI呈一定的上升趋势,变化率分别为0.0014 NDVI/a(P0.05=0.001),0.0009 NDVI/a(P0.05=0.001),落叶林、草原、作物、草原化荒漠NDVI没有显著变化(P0.05＞0.05);②年均NDVI与降水、温度相关性分析结果表明,49.00%的地区年均NDVI与年降水量呈正相关,52.33%的地区NDVI与春季降水量正相关,33.69%的地区NDVI与夏季降水量正相关,70.00%的地区年均NDVI与各季气温弱相关,仅17.78%的地区年均NDVI与年均气温正相关;6种植被类型NDVI与降水、气温相关关系为,常绿林、高山草甸年均NDVI与年均气温分别低度、显著正相关性,相关系数分别为0.432(P0.05=0.05)、0.557(P0.05=0.009);草原、作物与年降水量分别显著、低度正相关,相关系数分别为0.5111(P0.05=0.018)、0,476(P0.05=0.029);落叶林NDVI与夏、冬季降水量低度正相关,相关系教分别为0.415(P0.05=0.061)、0.461(P0.05=0.035);草原化荒漠NDVI与春季降水量正相关但不显著,相关系数为0.415(P0.05=0.061).     

基于TMS320C6202 DSP的运动目标跟踪系统

本文描述了一种以TMS320C6202数字信号处理器为核心的高速图像处理板和图像实时采集卡及摄像头构成的实时运动跟踪系统。提出了一种快速图像匹配的相关跟踪算法,给出了在复杂背景下跟踪飞机的实验结果。实验证明该系统性能可靠,跟踪效果较好,并有较高的实时性。     

A novel approach for part family formation using K-means algorithm

The reconfigurable manufacturing system （RMS） is the next step in manufacturing, allowing the production of any quantity of highly customized and complex parts together with the benefits of mass production. In RMSs, parts are grouped into families, each of which requires a specific system configuration. Initially system is configured to produce the first family of parts. Once it is finished, the system will be reconfigured in order to produce the second family, and so forth. The effectiveness of a RMS depends on the formation of the optimum set of part families addressing various recon figurability issues. The aim of this work is to establish a methodology for grouping parts into families for effective working of RMS. The methodology carried out in two phases. In the first phase, the correlation matrix is used as similarity coefficient matrix. In the second phase, agglomerative hier archical Kmeans algorithm is used for the parts family for mation resulting in an optimum set of part families for reconfigurable manufacturing system.     

Association of Obesity with Hormonal Imbalance in Infertility: A Cross-Sectional Study in North Indian Women

Hormones play an important role in the development and regulation of reproductive function and the menstrual cycle of women. Extremes of body weight tend to affect the homeostasis of the hypothalamo–pituitary–gonadal axis. This cross-sectional study was carried out in 113 women (57 with primary infertility and 56 with secondary infertility) in the age group 20–35 years, presenting for hormonal evaluation of infertility in a tertiary care hospital. After preliminary clinical evaluation, anthropometric indices (height, weight, BMI, waist circumference and waist hip ratio) were measured in all subjects. Fasting blood sample drawn on second/third day of menstrual cycle was analysed for serum luteinizing hormone, follicle stimulating hormone (FSH), prolactin and thyroid stimulating hormone (TSH). Serum FSH levels showed a significant positive correlation with indicators of central obesity (waist circumference and waist hip ratio in both the study groups). In primary infertility, significant positive correlation was also observed between serum FSH levels and other markers of obesity like body weight, hip circumference and BMI. In secondary infertility, serum prolactin and serum TSH levels demonstrated a significant positive correlation with body weight and BMI. Obesity is associated with hormonal derangements which are responsible for infertility. In overweight women with infertility, weight loss should be considered as a first line treatment.     

Incorporating group recommendations to recommender systems: Alternatives and performance

In collaborative filtering recommender systems recommendations can be made to groups of users. There are four basic stages in the collaborative filtering algorithms where the group’s users’ data can be aggregated to the data of the group of users: similarity metric, establishing the neighborhood, prediction phase, determination of recommended items. In this paper we perform aggregation experiments in each of the four stages and two fundamental conclusions are reached: (1) the system accuracy does not vary significantly according to the stage where the aggregation is performed, (2) the system performance improves notably when the aggregation is performed in an earlier stage of the collaborative filtering process. This paper provides a group recommendation similarity metric and demonstrates the convenience of tackling the aggregation of the group’s users in the actual similarity metric of the collaborative filtering process.     

The attenuation of correlation coefficients: a statistical literacy issue

Much of the science reported in the media depends on correlation coefficients. But the size of correlation coefficients depends, in part, on the reliability with which the correlated variables are measured. Understanding this is a statistical literacy issue.     

基于灰色理论的A级汽车销量影响因素分析与预测

研究探讨影响汽车销售量的主要因素和预测汽车销售量的数学模型,无论是对于整体掌控汽车市场的发育与成长态势的政策制定者,还是对于研究市场行情以制定营销策略的汽车厂商而言,都具有十分重要意义。为了找出A级汽车销量的影响因素和对其销量进行预测,以选车网提供的深受广大消费者欢迎,受众广、性价比高的12种紧凑型A级汽车有关数据为例,利用灰色系统有关理论建模的优势,针对影响A级汽车销售量因素和依据历史销售量数据对汽车销售量进行预测两个问题,分别采用灰色关联分析法和灰色系统GM(1,1)模型进行了分析和建模,以期达到指导A级汽车的生产和营销的目的。     

高校图书馆文献借阅服务与大学生学习成果关联性实证研究

大学生知识获得能力的提高和图书馆服务之间存在着密切的联系,文章以大学生在图书馆的文献借阅数量和平均学分绩点的关系为出发点,从实证角度探讨图书馆服务对大学生学习成果的影响,研究成果显示大学生获得的学习成果和图书馆利用之间存在正相关关系。     

我国青年男篮身体形态、素质与运动技术相关性分析

文章运用实验法分析我国青年男篮运动员身体形态、素质与运动技术的相关性,建立线性回归方程,为优秀篮球运动员的选材提供参考。结果显示,我国青年男篮运动员整体状况一般,但处于生长发育期,仍有发展空间;克托莱指数与身高、体重、伸臂高均呈正相关,而体质指数与体重显著相关,与身高无线性关系;伸臂高与运动技术水平正相关,身高、体重与三角移动负相关,与下肢爆发力、力量素质及速度素质正相关,纵跳、摸高与伸臂高正相关,而与投篮、运球、脚步移动等技术呈负相关,且大部分运动技术与身体素质间无线性相关。