Static and dynamic accuracy of a magnetic-inertial measurement unit used to provide racket swing kinematics

Magnetic-inertial measurement units (MIMUs) are becoming more prevalent in sports biomechanics and may be a viable tool to evaluate kinematic parameters. This study examined the accuracy of a MIMU to estimate orientation angles under static conditions and dynamically from a squash racket during a forehand drive shot. A MIMU was mounted onto a goniometer and moved through 0–90°, with static data collected at 10° increments during 10 repetitions of all three axes. Typical error analyses showed the MIMU to be very reliable (TE ≤ 0.03°). MIMU accuracy was determined via intraclass correlation coefficients (ICC) (r > 0.999, p < 0.001). An ordinary least products regression showed no proportional bias and minimal fixed bias for all axes. Dynamic accuracy was assessed by comparing MIMU and optical motion capture data of squash racket swing kinematics. A MIMU was fixed onto a racket and 10 participants each hit 10 forehand shots. Mean orientation angle error at ball impact was <0.50° and ICC showed very high correlations (r ≥ 0.988, p < 0.001) for all orientations. Swing phase root mean squared errors were ≤2.20°. These results indicate that a MIMU could be used to accurately and reliably estimate selected racket swing kinematics.     

The influence of water depth on kinematic and spatiotemporal gait parameters during aquatic treadmill walking

The purpose of this study was to investigate kinematic and spatiotemporal variables of aquatic treadmill walking at three different water depths. A total of 15 healthy individuals completed three two-minute walking trials at three different water depths. The aquatic treadmill walking was conducted at waist-depth, chest-depth and neck-depth, while a customised 3-D underwater motion analysis system captured their walking. Each participant’s self-selected walking speed at the waist level was used as a reference speed, which was applied to the remaining two test conditions. A repeated measures ANOVA showed statistically significant differences among the three walking conditions in stride length, cadence, peak hip extension, hip range of motion (ROM), peak ankle plantar flexion and ankle ROM (All p values < 0.05). The participants walked with increased stride length and decreased cadence during neck level as compared to waist and chest level. They also showed increased ankle ROM and decreased hip ROM as the water depth rose from waist and chest to the neck level. However, our study found no significant difference between waist and chest level water in all variables. Hydrodynamics, such as buoyancy and drag force, in response to changes in water depths, can affect gait patterns during aquatic treadmill walking.     

Superior short-term learning effect of visual and sensory organisation ability when sensory information is unreliable in adolescent rhythmic gymnasts

Rhythmic gymnasts specialise in dynamic balance under sensory conditions of numerous somatosensory, visual, and vestibular stimulations. This study investigated whether adolescent rhythmic gymnasts are superior to peers in Sensory Organisation test (SOT) performance, which quantifies the ability to maintain standing balance in six sensory conditions, and explored whether they plateaued faster during familiarisation with the SOT. Three and six sessions of SOTs were administered to 15 female rhythmic gymnasts (15.0 ± 1.8 years) and matched peers (15.1 ± 2.1 years), respectively. The gymnasts were superior to their peers in terms of fitness measures, and their performance was better in the SOT equilibrium score when visual information was unreliable. The SOT learning effects were shown in more challenging sensory conditions between Sessions 1 and 2 and were equivalent in both groups; however, over time, the gymnasts gained marginally significant better visual ability and relied less on visual sense when unreliable. In conclusion, adolescent rhythmic gymnasts have generally the same sensory organisation ability and learning rates as their peers. However, when visual information is unreliable, they have superior sensory organisation ability and learn faster to rely less on visual sense.     

中国乒乓球男队主要对手的技战术分析

运用文献法、录像观察法、三段技术统计法,对当前中国乒乓球男队的主要竞争对手柳承敏、萨姆索诺夫、波尔进行了微观的技术剖析,并提出了相应的应对策略。研究还表明,如果继续沿用以前的三段技术评估标准,应做如下补充：一段不及格,两段优秀和一段不及格,一段及格,一段优秀,均可获胜;如果不沿用以前的评估标准,应做如下修敌：把相持段的得分率和使用率的数值下调,下调的幅度应做进一步的、大样本的研究。     

Internet‐based Science Learning: A review of journal publications

Internet‐based science learning has been advocated by many science educators for more than a decade. This review examines relevant research on this topic. Sixty‐five papers are included in the review. The review consists of the following two major categories: (1) the role of demographics and learners' characteristics in Internet‐based science learning, such as demographic background, prior knowledge, and self‐efficacy; and (2) the learning outcomes derived from Internet‐based science learning, such as attitude, motivation, conceptual understanding, and conceptual change. Some important conclusions are drawn from the review. For example, Internet‐based science learning is equally favorable, or in some cases more so, to learning for female students compared to male students. The learner's control is essential for enhancing students' attitudes and motivation toward learning in Internet‐based science learning environments. Nevertheless, appropriate guidance from teachers, moderators, or the Internet‐based learning environment itself is still quite crucial in Internet‐based science learning. Recommendations for future research related to the effects of Internet‐based science learning on students' metacognitive reflections, epistemological development, and worldviews are suggested.     

研究型教学在《中国近现代史纲要》教学中的运用初探

在《中国近现代史纲要》中运用研究型教学是实现该课程教学目的的需要,有利于培养学生能力和提高教师素养;组织和实施研究型教学,应该遵循教学规律,从课前准备、小组研讨、汇报交流、活动评价等环节规范其教学流程;同时,要精心设计研究问题,解决内容多课时少的矛盾,营造民主和谐的教学氛围。     

对图书馆OPAC分类数据的分析

本文指出了OPAC分类数据中存在的问题，并对存在问题的原因进行了剖析，提出了改进建议。     

Managing IT-enabled transformation in the public sector: A case study on e-government in South Korea

The implementation of e-government is a burgeoning phenomenon across the globe. It improves and enhances the infrastructures and services provided to the citizens. However, a review of the IS literature reveals that research on the implementation of e-government is rather limited, which could be due to the general misconception of the public sectors as rigid and risk-averse establishments. The shortage of studies on e-government’s implementation presents a knowledge gap that needs to be plugged. This gap is significantly amplified by the increasing number of e-government initiatives being implemented by governments in recent years. This paper describes and analyzes South Korea’s Supreme Court Registry Office, which has implemented e-government. The case study discusses practical implications and suggests future research areas. Findings of the study include the alignment of technology and business processes, integration of resources into core business activities, integrating stakeholders’ trust and commitment, and better understanding of the role of organizational learning, which can enhance the adoption and institutionalization of e-government initiatives.     

论农村学校课程资源开发的必要性及其条件

开发学校的课程资源是新课程提出的重要理念之一,对广大的农村学校而言,在实现课程目标的、弥补其他课程资源的不足以及形成适合农村和地方的课程三方面有其必要性。而要进行这种开发,既需要教师的课程意识和开发能力,同时也需要学校提供合适的外部环境。     

肿瘤学核心期刊中"腊肠切片"稿件存在问题分析

调查发现,5种肿瘤学核心期刊2005年发表的研究论文中有如下情况:将同一个研究结果分成多篇文章发表,且有50%以上的内容重复.初步分析其原因,提出一些解决方法,以引起更多编辑人员和科研人员的注意及重视.