排序方式： 共有79条查询结果，搜索用时 390 毫秒
51.
Yukiko Sakai Kuniko Sato Naoko Suwabe Hiroko Gemba Atsutake Nozoe Jeong‐Wook Seo Hye Yang Kim 《Health information and libraries journal》2014,31(3):239-242
This is the 11th in a series of articles exploring international trends in health science librarianship. The previous article in this series looked at the Far East (Greater China, Hong Kong and Taiwan). The current issue surveys developments in Japan and Korea. The next issue will explore trends in South Asia (India, Pakistan, Bangladesh and Sri Lanka). Next year all four issues will be devoted to trends in four regions in Africa (Southern Africa, East Africa, West Africa and North Africa. JM 相似文献
52.
Flight dynamics of the screw kick in rugby 总被引：1，自引：1，他引：0
This paper describes the aerodynamic forces and the flight trajectory for the screw (spiral) kick in rugby. The screw kick
is defined as that which causes the ball to spin on its longitudinal axis. The aerodynamic forces acting on a rugby ball spinning
on its longitudinal axis were measured in a wind tunnel using a six-component strut type balance. It was found that the drag,
the lift and the pitching moment depend on the angle of attack, while the side force (Magnus force) depends on both the spin
rate and the angle of attack in the range where the wind speed lies between 15 and 30 m s-1 and the spin rate is between 1 and 10 revolutions per second. Moreover, the flight trajectory was obtained by integrating
the full nonlinear six degrees of freedom equations of motion on the basis of aerodynamic data. In a simulation, a ball spinning
on its longitudinal axis tended to hook toward or away from the touchline even if the velocity and angular velocity vectors
were parallel to the touchline. The direction of the hook depends on the direction of the angular velocity vector. The initial
direction of the hook depends on the relationship between the flight path angle and the pitch angle as well as the direction
of the angular velocity vector. 相似文献
53.
We report a refillable and valveless drug delivery device actuated by an external magnetic field for on-demand drug release to treat localized diseases. The device features a pear-shaped viscoelastic magnetic membrane inducing asymmetrical deflection and consecutive touchdown motion to the bottom of the dome-shaped drug reservoir in response to a magnetic field, thus achieving controlled discharge of the drug. Maximum drug release with 18 ± 1.5 μg per actuation was achieved under a 500 mT magnetic flux density, and various controlled drug doses were investigated with the combination of the number of accumulated actuations and the strength of the magnetic field. 相似文献
54.
The bubble-free and pulse-free fluid delivery is critical to reliable operation of microfluidic devices. In this study, we propose a new method for stable bubble-free and pulse-free fluid delivery in a microfluidic device. Gas bubbles are separated from liquid by using the density difference between liquid and gas in a closed cavity. The pulsatile flow caused by a peristaltic pump is stabilized via gas compressibility. To demonstrate the proposed method, a fluidic chamber which is composed of two needles for inlet and outlet, one needle for a pinch valve and a closed cavity is carefully designed. By manipulating the opening or closing of the pinch valve, fluids fill up the fluidic chamber or are delivered into a microfluidic device through the fluidic chamber in a bubble-free and pulse-free manner. The performance of the proposed method in bubble-free and pulse-free fluid delivery is quantitatively evaluated. The proposed method is then applied to monitor the temporal variations of fluidic flows of rat blood circulating within a complex fluidic network including a rat, a pinch valve, a reservoir, a peristaltic pump, and the microfluidic device. In addition, the deformability of red blood cells and platelet aggregation are quantitatively evaluated from the information on the temporal variations of blood flows in the microfluidic device. These experimental demonstrations confirm that the proposed method is a promising tool for stable, bubble-free, and pulse-free supply of fluids, including whole blood, into a microfluidic device. Furthermore, the proposed method will be used to quantify the biophysical properties of blood circulating within an extracorporeal bypass loop of animal models. 相似文献
55.
Literature in the United States provides many examples of no difference in student achievement when measured against the mode of test administration i.e., paper‐pencil and online versions of the test. However, most of these researches centre on ‘regular’ students who do not require differential teaching methods or different evaluation processes and techniques. This research provides evidence that students who have learning disabilities, like their counterparts in the regular educational programme, do not lag behind in computer adaptation and use. The study, using differential item functioning analysis with an ‘external’ variable and an analysis of covariance, shows that items and tests can be created to have no practical differences in the mode of administration for this special group of students, and as such, is in keeping with the trend for using online testing with its many advantages (cost savings, flexibility in administration, etc.) in lieu of the paper and pencil version of the test. 相似文献
56.
This study examines US and South Korean journalists' use of sources and their perceptions of source credibility in covering the six-party talks on North Korea's nuclear ambitions. In particular, this study analyzes the relationship between journalists' perceptions of source credibility and the media's source use in terms of the aggregate and individual levels. Results of content analysis of US and South Korean newspapers are compared with data from a survey of US and South Korean journalists who covered the six-party nuclear talks. Government officials are dominant sources in media coverage of the talks because of their high level of accessibility and credibility. US and South Korean journalists assigned the greatest credibility to government officials of their own country. The two groups showed significant differences in their perceptions of credibility of South Korean officials, North Korean officials, Japanese officials, and Japanese experts. Moreover, this study finds that individual journalists' perceptions of source credibility were as strongly correlated with their individual use of sources as with the news media's aggregate use of sources. Implications of the findings are discussed in the context of media sociology, in particular gatekeeping. 相似文献
57.
The purpose of this study was to analyze the effects of collaborative activities on group identity in a virtual world such as Second Life. To achieve this purpose, this study adopted events that promoted participants' interactions using tools inherent in Second Life. The interactive tools given to the control group in this study included ‘permissions to move, copy, edit’, ‘give item’, ‘chat’, and ‘send instant message’. In addition to these tools, special tools of ‘give item for praise’ and ‘pollster’ were given to the experimental group. The two groups were compared using scores of group identity, which has nine subcategories. The experimental group showed higher scores in five subcategories than the control group. Thus, we concluded that the use of tools for facilitating participants' interactions is effective for the formation of group identity. 相似文献
58.
59.
Hyunjin Song 《Communication methods and measures》2018,12(1):1-24
The substantial increase in nested data such as egocentric network data pose unique challenges to researchers, including how to adequately model the mechanisms and processes in which hypothesized effects operates within the complex interdependencies among social actors. While there is a growing interest in identifying the causal mechanisms and their contingencies using such nested structured data, the direct application of principles of (moderated) mediation analysis within traditional multilevel modeling framework is ambiguous and controversial. In this article, I provide a tutorial illustrating an approach to assessing mediation hypotheses based on path-analytic framework popularized by Hayes (2013). Focusing on estimation and inference of indirect effects with regard to nested data structure, I provide examples of the analysis within the context of egocentric network data, and illustrate implementation using Mplus software. 相似文献
60.
The development and current status of special education in South Korea are described and contrasted to that of the United States. South Korean special education was initiated in the 1890s by U.S. missionaries. Later, Japanese influence was considerable, especially on its regular educational programs. Special programs are available for five classifications of disabilities. Its major national special education legislation contains numerous provisions similar to P.L. 94-142. However, various conditions may impede the further development of services, including a high teacher-pupil ratio, the reliance on self-contained programs, negative attitudes toward people with disabilities, and lack of advocacy groups. Further initiatives require considerable research and policy debate among South Koreans. 相似文献