Effect of different loading conditions on running mechanics at different velocities     

Germán Carretero-Navarro  Doménico Cherubini  Wolfgang Taube 《European Journal of Sport Science》2019,19(5):595-602

Weighted vests are widely used to improve running economy and performance. However, it is not well-studied how running mechanics are adapted to counteract the higher peak vertical ground reaction forces (Fpeak) while running with such a device. Therefore, the present study aimed to investigate the effects of different loading conditions on running mechanics at different velocities. Thirteen subjects participated in two separate sessions one week apart. In the first session, maximal aerobic speed (MAS) was determined through a maximal incremental running test while in the second session, they were instructed to run during one minute under different loading (0%, +10% and +20% of body mass [BM]) and velocity (60%, 80% and 100% of MAS) conditions in a random order. Spatiotemporal data were recorded and then running mechanics modelled using the spring-mass model. The main results indicated that vertical and leg stiffness (Kvert and Kleg, respectively) were increased (P?P?>?.05) when load was changed. At the same time, alterations of the running kinematics were observed such as longer contact times, reduced flight times, stride frequencies and step lengths, as well as an increase of the centre of mass dynamics. Based on these results it is assumed that runners maintain a certain stiffness level for each velocity despite different loading conditions. As a consequence, Fpeak increases and this probably causes spatiotemporal adjustments in the movement kinematics.  相似文献   

一种机载重轨InSAR高精度三维定位方法     

董小桐  韩春明  岳昔娟  赵迎辉 《中国科学院大学学报》2019,36(6):844-850

在重轨干涉实际测量中，两次飞行航迹难以保持高度重合，飞行高度和姿态不稳定，干涉图像对存在明显不规则的相对形变，难以进行三维定位。通过分析重轨机载InSAR图像对的几何形变和形成原因，提出一种从精准的InSAR成像几何关系出发，通过修正成像参数，实现机载重轨InSAR高精度三维定位的方法。该方法通过引入地面控制点，实现干涉图像对精准的相对定位，生成高精度DEM；并利用高精度DEM，实现机载重轨InSAR高精度三维定位。对比检查点实测结果和定位结果，表明该方法可有效地解决机载重轨InSAR的三维定位困难的问题。  相似文献   

The RIX Wiki: the use of multimedia advocacy to support person-centred planning in a special needs secondary school – implications for current policy and practice     

Gosia Kwiatkowska  Andy Minnion  Jo Finch 《Support for Learning》2021,36(4):512-531

The article documents findings from a pilot study undertaken in 2012–2013 in a special needs secondary school in the England, that trialled the use of a multimedia advocacy tool, “The RIX Wiki”. The trial was part of the pathfinder programme, which aimed to reform existing Special Education Needs provision, from the system of statementing to one of developing education health care plans. The reforms became enshrined in the Children and Families Act (2014). The findings were overall positive and helped with person-centred planning processes. The discussion is framed within current and future policy directives. We argue that multimedia advocacy approaches and software tools, like the “RIX Wiki” will have a continued role to play in ensuring the needs, aspirations and choices of children and young people with learning disabilities remain central.  相似文献   

Students’ achievement goals and beliefs of causes of success: Temporal relations and gender differences     

《Contemporary educational psychology》2021

According to the goal orientation model, students’ achievement goals and beliefs are interrelated. Within this framework, research and theory have so far assumed that achievement goals are associated with students’ beliefs of causes of success, the latter representing students’ subjective beliefs about the factors contributing to success at school. So far, this line of research has been restricted to a few cross-sectional studies. We examined the temporal relations between achievement goals (mastery, performance-approach, and performance-avoidance goals) and students’ beliefs of causes of success, the latter operationalized by asking the students to rate the subjective importance of diligence, effort, and ability for school success. Achievement goals and beliefs of causes of success were measured twice with a time lag of one school year with a sample of N = 2044 German secondary school students. Cross-lagged panel models were estimated to examine the temporal relations between achievement goals and beliefs of causes of success while controlling for students’ secondary school track, socio-economic status, and Grade Point Average. Former mastery goals were found to be positively related to later importance ratings of diligence for school success; former performance-approach goals were found to be positively related to later importance ratings of ability. Boys and girls were found to display similar relations among constructs but they showed differential mean levels on both the achievement goal constructs and the beliefs of causes of success. Implications for research on achievement goals and practice using intervention approaches are discussed.  相似文献   

Audience management,online turbulence and lurking in social networking services: A transactional process of stress perspective     

《International Journal of Information Management》2021

In social networking services (SNSs), users’ unclear understanding of the large and invisible audience increases the chances of online turbulence, which is a key source of SNS-induced stress. This growing phenomenon has gained increasing attention in academia and industry due to the undesirable consequences for users and SNS platforms. In this study, we draw from the transactional model of stress to examine how audience management strategies impact online turbulence and lead to neglected unintended audience concern and lurking. We also investigate the role of self-monitoring as a stress inhibitor. We test our model with data collected from 301 SNS users. The results show that the four types of audience management strategies have different effects on online turbulence, which significantly impacts neglected unintended audience concern especially when users have high self-monitoring skills. We believe that this work contributes, both from scientific and practical standpoints, to the understanding of the interventions and stressful responses of online turbulence in SNSs.  相似文献   

灰色预测法在情报研究中的应用研究综述     

张晶晶  李泽霞 《图书情报工作》2021,64(24):106-114

[目的/意义] 灰色预测法可有效处理情报研究中广泛存在的小样本数据，通过对灰色预测法在情报研究中的应用情况进行梳理，总结其在应用过程中存在的不足，为灰色预测法在情报研究中的进一步应用提供参考。[方法/过程] 通过综述情报研究中涉及灰色预测法的相关文献，从数据选取、模型构建和解决的问题等方面对情报研究中灰色预测法的应用进行概述，总结当前情报研究中灰色预测法的应用所存在的问题，并提出改进建议。[结果/结论] 在方法应用上，已有研究主要采用数列灰预测，且模型集中在单变量灰色预测模型，根据预测对象不同，灰色预测法已经在包括期刊分析、图书馆运行管理、热点主题分析及科研机构评价方面得到了很好的应用，未来可根据预测对象特点及研究目标尝试不同的灰色预测方法，扩宽灰色预测法在其他方面的情报研究问题中的应用。  相似文献   

Platform-based customer agility: An integrated framework of information management structure,capability, and culture     

《International Journal of Information Management》2021

Platform-based customer agility is the ability to leverage the voice of the customer on a platform to achieve market intelligence and to explore competitive action opportunities. Prior studies have indicated the critical role of customer agility in enabling the survival and prosperity of contemporary organizations in a turbulent business environment, although how to develop this capability is not answered. The current research attempts to fill this theoretical gap. Drawing on the information management literature, we propose an integrative information management framework to investigate the process of developing customer agility. By conducting a case study of a leading e-commerce platform in China, we identify three types of platform-based customer agility (i.e. reactive customer agility, proactive customer agility, and coactive customer agility) in different phases of the growth of the platform. Furthermore, a process model is developed from the case study. It shows that platform-based customer agility is achieved by establishing information management structure, developing information management capability, and instilling information management culture. This study contributes to the knowledge on customer agility and information management. Detailed recommendations are also provided for potential practitioners.  相似文献   

可持续发展视角下全民健身服务体系的内涵解析     

梁法泽  聂瑞莲  侯玉灵 《体育科技文献通报》2020,(1):10-12

本文以可持续发展为视角,阐述了可持续发展视角下全民健身服务体系内涵。利用文献资料法、实地考察法及专家访谈法,对可持续发展视角下全民健身服务体系发展现状进行了简单分析。进一步探究了可持续发展视角下全民健身服务体系建设路径,以期为可持续发展视角下全民健身服务体系建设提供有效的借鉴。  相似文献   

Information resource orchestration during the COVID-19 pandemic: A study of community lockdowns in China     

《International Journal of Information Management》2020

The outbreak of the COVID-19 pandemic has created significant challenges for people worldwide. To combat the virus, one of the most dramatic measures was the lockdown of 4 billion people in what is believed to be the largest quasi-quarantine in human history. As a response to the call to study information behavior during a global health crisis, we adopted a resource orchestration perspective to investigate six Chinese families who survived the lockdown. We explored how elderly, young and middle-aged individuals and children resourced information and how they adapted their information behavior to emerging online technologies. Two information resource orchestration practices (information resourcing activities and information behavior adaptation activities) and three mechanisms (online emergence and convergence in community resilience, the overcoming of information flow impediments, and the application of absorptive capacity) were identified in the study.  相似文献   

Student success pocket-graphic: a mountain of data transformed     

Karen Briere  Kelly Drifmeyer 《Public Services Quarterly》2020,16(1):48-58

Abstract

How does a small community college library, without marketing experience or budget, advocate for its value to a campus community and its administrators? We did so by creating an engaging, bright, and easy-to-read “pocket-graphic.” In this column, we reflect on the process of shaping a multi-use product out of a mountain of data. Through research in design practices, field observations of popular information tools, and an uncomfortable step into braggadocio, we learned to articulate the successes of our library. Our “pocket-graphic” told our story, yes – but it also provoked surprise, questions (“you really have all that?”) and delight in the lesser known successes (“you really DO all that!”). In the process, we connected our students more deeply to helpful services and resources, faculty to supportive instruction, and positively changed the tone of conversation with all our stakeholders. By turning data points into selling points, we found insights and a focus that moved our own development forward, helping ourselves to define improved priorities for advancing our critical role in student success.  相似文献