无人机转角控制中的虚拟建模过程分析

无人机转角控制是无人机飞行中的关键。由于在对无人机进行操控时,存在一定的时间滞后性,利用传统的基于虚拟现实技术开发的无人机转角控制系统没有考虑时间的滞后性因素带来的影响,使得训练效果达不到实际操控无人机的要求,导致在实际操控中提高了无人机的坠机风险。为此,提出一种基于虚拟现实技术优化算法的无人机转角控制方法,建立无人机转角控制模型,得到转角控制参数,利用得到的时间误差进行补偿,得到新的无人机转角状态模型,利用新模型能够实现对无人机转角的精确控制。仿真实验结果表明,利用基于虚拟现实技术优化算法的无人机转角控制方法能够对无人机转角进行精确控制,效果令人满意。     

In support of sport: Examining the relationship between community sport organizations and sponsors

Sponsorships are a critical resource for nonprofit community sport organizations (CSOs) that are increasingly experiencing pressure to generate funding beyond their traditional source of membership revenues. In order to optimize this alternative source, it is important to understand the nature of the relationship between CSOs and sponsors and its impact on those clubs. Scales were developed, and presidents of CSOs (N = 189) completed a corresponding survey that measures the extent to which clubs’ relationship with their key sponsor was characterized by various elements of the relationship process and relationship outcomes. Operational competence was a consistent predictor of the impact of the sponsor relationship on club program/operations and community presence, and further enhanced the impact of long-standing sponsorships. Notably, operational competence was perceived to be required to a lesser extent in CSO–sponsor relationships than in the other process elements. Implications for effective CSO–sponsor relationships and directions for future research are presented.     

经济发展、产业结构调整与城镇建设用地规模控制

马鞍山市目前正处于城市产业结构调整及功能转型过程中.该研究以马鞍山市为例,通过统计描述、定性分析,系统地考察了人口城市化水平、经济发展水平、产业结构调整与城镇建设用地规模之间的关系,研究了在经济发展过程中如何合理确定和控制城镇建设用地规模的问题,并提出了一个待验证的假说.随后,用经济计量模型:Yi=α β1X1i β2X2i β3X3i εi验证了所提出的假说,并估计人口城市化水平、经济发展水平、产业结构调整等社会经济驱动力因子对城镇建设用地规模的影响.计量模型估计结果表明,城市化水平、经济发展水平与产业结构调整对城镇建设用地规模的影响具有不同的作用方向,城市化水平、经济发展水平带动了城市用地规模的扩张,而产业结构调整则有利于城市用地的集约化和用地结构的优化.研究结果验证了所提出的假说,其结论可以有力支持当前的城市产业结构调整以及功能转型政策,对其他的转型城市而言,也具有重要的借鉴意义.     

On robust stabilization of uncertain stochastic time-delay systems—an LMI-based approach

In this paper, we first deal with the robust stability of uncertain linear stochastic differential delay systems. The parameter uncertainties are time-varying and unknown but are norm-bounded via two types of uncertainties, and the delays are time invariant. We then extend the proposed theory to discuss the robust stabilization of uncertain stochastic differential delay systems. These results are given in terms of linear matrix inequalities. Two examples are presented to illustrate the effectiveness.     

Academic delay of gratification and children's study time allocation as a function of proximity to consequential academic goals

Students (N = 302) in Chinese elementary schools were assessed regarding their academic delay of gratification (ADOG) and reported the time they devoted to non-school study and playtime during an extended interval prior to taking a high-stakes final exam. Students high compared those low in ADOG were more likely to spend time studying and less time playing several weeks prior to the exam. Growth curve analyses verified, however, that this difference diminished as a function of the temporal proximity to the exam, and that the group differences were non-existent just before the exam. Associations between ADOG and students' academic motivation and use of learning strategies replicated those obtained previously with adults in the USA. Results contribute to the general literatures on volition, homework and the dynamics of conflicting goals and action tendencies.     

Trajectories of maternal verbal aggression across the middle school years: associations with negative view of self and social problems

Objective

The primary research objective was to explore the relationship between trajectories of maternal verbal aggression (VA) experienced by low-income, community middle school students across a three-year period and outcomes that have been found to be related to VA in previous work, including a negative view of self and social problems.

Method

Longitudinal data were collected from 421 youth (51.8% male) attending two middle schools over 3 years using a multiple-informant survey design. K-means cluster analysis was used to identify trajectories of VA using youth ratings of the Conflict Tactics Scale: Parent-Child (Straus, Hamby, Finkelhor, Moore, & Runyan, 1998). Dependent variables were self-reported depression, self-esteem, delinquency, and peer victimization as well as peer-rated aggression and sensitive-isolated reputation.

Results

Four trajectory groups of VA were identified: Low Stable, Increasing, Decreasing, and High Stable. The 3-year average occurrence of VA was: 1.31, 9.18, 10.24, and 31.14 instances, respectively. Gender-specific MANOVAs revealed dramatic differences between the High Stable and Low Stable groups. High Stable boys reported significantly more depressive symptoms, delinquency, peer overt and relational victimization, and were less likely to have a sensitive/isolated reputation than Low Stable boys. High Stable girls reported significantly more depressive symptoms, low self-esteem, delinquency, peer overt and relational victimization and were rated by peers as having more aggressive/disruptive and relationally aggressive reputations than Low Stable girls. Girls in the High Stable group were more likely than other youth to report levels of depressive symptoms and delinquency >1 SD above the mean, while boys in the High Stable group were more likely to report levels of delinquency >1 SD above the mean. The Increasing and Decreasing groups also demonstrated significantly poorer functioning than the Low Stable group on most outcomes. Growth curve analysis revealed that VA showed a contemporaneous association with self-reported delinquency suggesting these factors are closely related.

Conclusions

Any level of VA greater than the 1–2 instances per year reported by youth in the Low Stable group was associated with less favorable outcomes.     

Predicting citation counts based on deep neural network learning techniques

With the growing number of published scientific papers world-wide, the need to evaluation and quality assessment methods for research papers is increasing. Scientific fields such as scientometrics, informetrics, and bibliometrics establish quantified analysis methods and measurements for evaluating scientific papers. In this area, an important problem is to predict the future influence of a published paper. Particularly, early discrimination between influential papers and insignificant papers may find important applications. In this regard, one of the most important metrics is the number of citations to the paper, since this metric is widely utilized in the evaluation of scientific publications and moreover, it serves as the basis for many other metrics such as h-index. In this paper, we propose a novel method for predicting long-term citations of a paper based on the number of its citations in the first few years after publication. In order to train a citation count prediction model, we employed artificial neural network which is a powerful machine learning tool with recently growing applications in many domains including image and text processing. The empirical experiments show that our proposed method outperforms state-of-the-art methods with respect to the prediction accuracy in both yearly and total prediction of the number of citations.     

国际大型体育赛事与中国国家形象的时代特征及发展机遇*

我国从近代开始参与国际大型体育赛事,到目前为止已经成为参与、举办国际大型体育赛事较多的国家。在不同的历史阶段,国际大型体育赛事提升国家形象表现出不同的时代特征。当前,一带一路国家战略的积极实施、中国特色大国外交战略的积极推广以及体育强国建设的全面推进,为国际大型体育赛事提升国家形象带来了崭新的发展机遇。     

体育课《因果关系感知量表》 在中国文化背景下的检验 ——以自我决定理论为基础

为干预青少年对体育课的自主性动机,引进体育课《因果关系感知量表》,并对该量表进行检验。初测选取400名大学一年级的学生作为被试,正式测试选取500名大学一年级的学生作为被试。检验结果表明,预测试体育课《因果关系感知量表》的语言等值性和测量等值性均可以接受;正式测试量表内部一致性信度、内容效度和结构效度良好;体育课《因果关系感知量表》符合心理学测量标准,是测量体育课自主性动机的可靠测量工具。     

图书馆科学发展的三维度量

图书馆科学发展观围绕人与自然、人与人之间关系的平衡,深入贯彻以人为本的核心理念;其阐述的三维特征,即数量维(发展度)、质量维(协调度)、时间维(持续度),使图书馆的发展具备了可观控性和可测度,从根本上科学地表征了对图书馆发展的完满追求.