飘球原理归结及其潜在威力之分析

本文以排球新规则有关发球条文为依据，运用流体力学原理，根据风洞实验、自由落体实验的结论与数据，对飘球的原理及特点进行了深入的探讨分析，揭示了现阶段挖掘飘球潜在威力的可行性与现实性。     

Resource utilisation and power relations of community sport clubs in the aftermath of natural disasters

Community sport clubs (CSCs) provide a number of benefits to local communities, while confronting challenges with finances and staffing. In Queensland, Australia, these challenges have been compounded by recent natural disasters including widespread flooding that have significantly impacted operations of CSCs. The current research explores the provision of resources to CSCs in the aftermath of flooding events in 2010 and 2011, as well as the influence on power relations between CSCs and resource providers. To address this research purpose, qualitative data were collected across nine site visits (focus groups, interviews) to affected CSCs. The data revealed three resource providers: volunteers and members, partner organisations and government. In addition, the results indicate that relations between CSCs and members and volunteers, partner organisations and government were impacted in different ways. Examples of resource providers wielding power over CSCs due to the provision of resources emerged, along with some evidence of mutual power and dependence and CSCs exerting power over resource providers. The results provide implications for CSC managers to be more proactive in relation to resourcing through developing strategies for network building and improved communication within networks.     

基于EDS算法识别电压暂降的研究

电压暂降是电力系统中常见的一种电气故障。本文针对电网中经常发生的电压暂降的情况,通过对实际中的电力系统中的电压暂降故障与正常运行时候的电压进行采集,并应用欧氏距离平方(EDS)算法对两种情况下的数据进行计算,统计出不同情况下即所得到的欧氏距离平方值的范围,同时比较一下大小。经过对大量的电压暂降情况进行计算比较,结果表明,发生电压暂降情况下,欧氏距离平方值要明显大于正常情况下的值,而且该算法步骤少,计算速度快,能够达到快速、准确检测电压暂降故障的目的。     

试析供电企业管理中的法律风险及防范措施

供电企业服务于公众事业,在营运过程中承担着较高的法律风险。文章首先分析了供电企业法律风险的各种表现形式,接着就法律风险的产生根源进行论述,最后提出全面防控法律风险的对策措施,以期为提升供电企业法律风险管理水平而抛砖引玉。     

基于效率视角的亚太地区知识竞争力研究

高效率的知识生产与转化是衡量区域知识竞争力的关键要素之一。沿用全球知识竞争力测度指标体系,将知识创新过程分为知识生产和转化两个子阶段,采用超效率数据包络分析方法从效率视角对亚太33个地区的知识竞争力进行测度分析。研究发现：(1)中国地区中两阶段都处于高效率区间的只有北京,上海和天津的知识生产高效率但知识转化低效率;(2)尽管大部分地区在知识生产阶段都取得了不错的效率,但知识转化效率偏低是亚太地区面临的普遍问题;(3)上海知识投入产出结构的均衡性优于其他中国大陆地区,北京投入产出偏离程度较大,两阶段投入均存在较大波动。     

An efficient method of addressing ectopic beats: new insight into data preprocessing of heart rate variability analysis

Heart rate variability (HRV) analysis is affected by ectopic beats. An efficient method was proposed to deal with the ectopic beats. The method was based on trend correlation of the heart timing signal. Predictor of R-R interval (RRI) value at ectopic beat time was constructed by the weight calculation and the slope estimation of preceding normal RRI. The type of ectopic beat was detected and replaced by the predictor of RRI. The performance of the simulated signal after ectopic correction was tested by the standard value using power spectrum density (PSD) estimation, whereas the results of clinical data with ectopic beats were compared with the adjacent ectopic-free data. The result showed the frequency indexes after ectopy corrected had less error than other methods with the test of simulated signal and clinical data. It indicated our method could improve the PSD estimation in HRV analysis. The method had advantages of high accuracy and real time properties to recover the sinus node modulation.     

电信机房综合管控系统设计

本文针对当前机房管理系统存在的不足,设计开发了一套电信机房综合管控系统软件,并构建了统一的网维机房综合监管平台。该系统可实现机房合同以及缴费数据等信息的自动化管理;提供能耗分析手段,为机房能耗改造提供依据;制定巡检模板和巡检流程,为代维人员制订明确的巡检任务要求,为考核代维人员提供明确的依据。     

Information resources estimation for accurate distribution-based concept drift detection

Machine learning applications must continually utilize label information from the data stream to detect concept drift and adapt to the dynamic behavior. Due to the computational expensiveness of label information, it is impractical to assume that the data stream is fully labeled. Therefore, much research focusing on semi-supervised concept drift detection has been proposed. Despite the large research effort in the literature, there is a lack of analysis on the information resources required with the achievable concept drift detection accuracy. Hence, this paper aims to answer the unexplored research question of “How many labeled samples are required to detect concept drift accurately?” by proposing an analytical framework to analyze and estimate the information resources required to detect concept drift accurately. Specifically, this paper disintegrates the distribution-based concept drift detection task into a learning task and a dissimilarity measurement task for independent analyses. The analyses results are then correlated to estimate the required number of labels within a set of data samples to detect concept drift accurately. The proximity of the information resources estimation is evaluated empirically, where the results suggest that the estimation is accurate with high amount of information resources provided. Additionally, estimation results of a state-of-the-art method and a benchmark data set are reported to show the applicability of the estimation by proposed analytical framework within benchmarked environments. In general, the estimation from the proposed analytical framework can serve as guidance in designing systems with limited information resources. This paper also hopes to assist in identifying research gaps and inspiring new research ideas regarding the analysis of the amount of information resources required for accurate concept drift detection.     

High-intensity interval running is perceived to be more enjoyable than moderate-intensity continuous exercise: Implications for exercise adherence

Abstract

The aim of this study was to objectively quantify ratings of perceived enjoyment using the Physical Activity Enjoyment Scale following high-intensity interval running versus moderate-intensity continuous running. Eight recreationally active men performed two running protocols consisting of high-intensity interval running (6×3 min at 90% [Vdot]O_2max interspersed with 6×3 min active recovery at 50% [Vdot]O_2max with a 7-min warm-up and cool down at 70% [Vdot]O_2max) or 50 min moderate-intensity continuous running at 70% [Vdot]O_2max. Ratings of perceived enjoyment after exercise were higher (P < 0.05) following interval running compared with continuous running (88 ± 6 vs. 61 ± 12) despite higher (P < 0.05) ratings of perceived exertion (14 ± 1 vs. 13 ± 1). There was no difference (P < 0.05) in average heart rate (88 ± 3 vs. 87 ± 3% maximum heart rate), average [Vdot]O₂ (71 ± 6 vs. 73 ± 4%[Vdot]O_2max), total [Vdot]O₂ (162 ± 16 vs. 166 ± 27 L) or energy expenditure (811 ± 83 vs. 832 ± 136 kcal) between protocols. The greater enjoyment associated with high-intensity interval running may be relevant for improving exercise adherence, since running is a low-cost exercise intervention requiring no exercise equipment and similar relative exercise intensities have previously induced health benefits in patient populations.     

关于有源高功率因数电子镇流器的讨论

讨论高性能电子镇流器系统必需具备的电路结构、功率因子校正电路的基本原理,介绍美国微线形公司(MicroLinearCorporation)生产的高性能电子镇流器控制器ML4831的基本工作原理、特点。