Development of a markerless optical motion capture system for daily use of training in swimming

The main objective of this research was to develop a markerless optical motion capture system that can be used for daily use in swimming training. The butterfly stroke was targeted since it is considered bilaterally symmetric in motion. The system consisted of a segmentation process to obtain the participant’s silhouettes and a matching process to estimate the pose of the participant. A variable thresholding method was used to extract the silhouettes to solve non-uniform illumination in the recorded swimming video. Prior to the matching process, the human body was modeled as a series of nine segments to help the matching process. The model was then mapped so that it aligned with the silhouettes, which were investigated by similarity of intensity value. To minimize the degree of freedom in image matching, the available joint motion in the swimming human simulation model was used as a priori information for kinematics data of the swimming motion. As a result, the rotation angle’s correlation coefficients between the references and result of the matching process were around 0.95 for trunk, thigh, shank, upper arm, forearm, hand and 0.78 for head, hip and foot. The rotation angle and the velocity of the center of mass were put into the swimming human simulation model for a dynamics analysis. The simulation results show that the velocity obtained in the experiment corresponded to the fluid force exerted on the lower and upper limbs. Consequently, the proposed system of obtaining the joint motion of the butterfly stroke is suitable for daily training and coaching.     

The effect of acceleration signal processing for head impact numeric simulations

Brain injury research in sport employs a variety of physical models equipped with accelerometers. These acceleration signals are commonly processed using filters. The purpose of this research was to determine the effect of applying filters with different cutoff frequencies to the acceleration signals used as input for finite element modeling of the brain. Signals were generated from reconstructions of concussion events from American football and ice hockey in the laboratory using a Hybrid III headform. The resulting acceleration signals were used as input for the University College Dublin Brain Trauma Model after being processed with filters. The results indicated that using a filter with a cutoff of 300 Hz or higher had little effect on the resulting strain measures. In some cases there was some effect of the filters on the peak linear (8–30g) and rotational measures (1000–4000 rad/s²), but little effect on the finite element strain result (approximately 2–6 %). The short duration and high magnitude accelerations, such as the puck impact, were most affected by the cutoff frequency of different filters.     

Designing,building, measuring,and testing a constant equivalent fall height terrain park jump

Previous work has presented both a theoretical foundation for designing terrain park jumps that control landing impact and computer software to accomplish this task. US ski resorts have been reluctant to adopt this more engineered approach to jump design, in part due to questions of feasibility. The present study demonstrates this feasibility. It describes the design, construction, measurement, and experimental testing of such a jump. It improves on the previous efforts with more complete instrumentation, a larger range of jump distances, and a new method for combining jumper- and board-mounted accelerometer data to estimate equivalent fall height, a measure of impact severity. It unequivocally demonstrates the efficacy of the engineering design approach, namely that it is possible and practical to design and build free style terrain park jumps with landing surface shapes that control for landing impact as predicted by the theory.     

从潮汕文化视角看潮汕民众体育价值取向与休闲体育现状

文章采用文献资料法、问卷调查法从潮汕文化视角研究潮汕民众的体育价值取向与民众参与休闲体育的现状和特点,为开展休闲体育及非遗民俗体育活动的传承提供参考.结果表明:潮汕民众体育价值取向倾向于个人品质和素质的塑造,注重族群间的交流和沟通;倾向于稳定、知足常乐,调节生活娱乐身心的价值功能;潮汕民众年龄越大,参与体育锻炼的频率有减少的态势;青少年人群在小长假进行体育休闲比例很小;随着年龄越大,潮汕民众越倾向于参加家族性团体的休闲活动.     

Seoul and the time in motion: urban form and political consciousness

Abstract

This paper explores the political effects of the cognitive change in the visual environment of colonial Seoul. It asks how the new urban imagery was perceived by the Korean population. It analyzes the ways in which they experienced urban forms, techniques of advertisement and urban infrastructure such as street‐cars and trains. It argues that the engagement of people with mobility, urban symbols and spectacles in the colonial city had stimulated different ways of seeing and thinking about who they were and what they had become, a new collective identity that is neither a subject of the Chos[obreve]n dynasty nor the Japanese colonial state. This paper demonstrates that colonial Seoul represented not only the technique of Japanese colonial subjugation but also generated a new grammar for imagining new identity and difference. The urban environment of the colonial city reflects not entirely a strategy of the colonizer but a tactic of the colonized in appropriating the different meanings of new social life, which was brought by, but not exclusively under, the control of colonial space and time.     

Shadow Play Drama Performed in China’s Xiaoyi

<正>Xiaoyi is a county located in the central part of north China’s Shanxi province. Over the sweep of history, many theatre forms were and developed in Xiaoyi, ...     

Materials Research in France: A Short-lived National Initiative (1982–1994)

This paper describes the French initiative in materials research against both a national and an international background, in an attempt to disentangle the local circumstances, which prompted this governmental initiative, and to characterize the specific profile of materials research in France. In presenting a biography of the interdisciplinary program in materials research (PIRMAT), we argue that: i) the PIRMAT denotes a failure of the French science policy in materials research; ii) the leadership of the CNRS led to a specific style of research, quite different from the engineering approach of Materials Science and Engineering, and characteristic of a French style in materials research.     

National,Regional and Global Perspectives of Higher Education and Science Policies in the Arab Region

In this paper we discuss the interaction between science policies (and particularly in the area of scientific research) and higher education policies in Gulf and Mediterranean Arab countries. Our analysis reveals a discrepancy between the two sub-regions with respect to integration in the global market, cooperation in scientific research and international mobility of students. The paper discusses the implications of the analysis of reform policies and higher education restructuring.