排序方式： 共有127条查询结果，搜索用时 15 毫秒
81.
David C. Oh 《Popular Communication》2017,15(4):269-282
The reaction video is an understudied area in YouTube and other online scholarship. Despite its limited scholarly attention, it is an influential site of meaning making, particularly for global youth cultures. Understanding polyculturalism as the suturing of self into multiple lineages, this project argues that Black American fans self-represent their K-pop fan interests as being salient to their racial identities. The videos construct identities that are not confined to the Black–White paradigm. Instead, YouTubers engage in fan practices of production, represent conformity to values within the fan community, articulate racially specific fan participation, and express concern for racially specific marginalizing discourses. Thus, the YouTube response video becomes a complicated site with multiple negotiations that reveal the self-production of polycultural identities. 相似文献
82.
In this paper, we propose a continuous flow droplet-based microfluidic platform for magnetic particle-based assays by employing in-droplet washing. The droplet-based washing was implemented by traversing functionalized magnetic particles across a laterally merged droplet from one side (containing sample and reagent) to the other (containing buffer) by an external magnetic field. Consequently, the magnetic particles were extracted to a parallel-synchronized train of washing buffer droplets, and unbound reagents were left in an original train of sample droplets. To realize the droplet-based washing function, the following four procedures were sequentially carried in a droplet-based microfluidic device: parallel synchronization of two trains of droplets by using a ladder-like channel network; lateral electrocoalescence by an electric field; magnetic particle manipulation by a magnetic field; and asymmetrical splitting of merged droplets. For the stable droplet synchronization and electrocoalescence, we optimized droplet generation conditions by varying the flow rate ratio (or droplet size). Image analysis was carried out to determine the fluorescent intensity of reagents before and after the washing step. As a result, the unbound reagents in sample droplets were significantly removed by more than a factor of 25 in the single washing step, while the magnetic particles were successfully extracted into washing buffer droplets. As a proof-of-principle, we demonstrate a magnetic particle-based immunoassay with streptavidin-coated magnetic particles and fluorescently labelled biotin in the proposed continuous flow droplet-based microfluidic platform. 相似文献
83.
This paper describes how questions can be characterized for question answering (QA) along different facets and focuses on questions that cannot be answered directly but can be divided into simpler ones so that they can be answered directly using existing QA capabilities. Since individual answers are composed to generate the final answer, we call this process as compositional QA. The goal of the proposed QA method is to answer a composite question by dividing it into atomic ones, instead of developing an entirely new method tailored for the new question type. A question is analyzed automatically to determine its class, and its sub-questions are sent to the relevant QA modules. Answers returned from the individual QA modules are composed based on the predetermined plan corresponding to the question type. The experimental results based on 615 questions show that the compositional QA approach outperforms the simple routing method by about 17%. Considering 115 composite questions only, the F-score was almost tripled from the baseline. 相似文献
84.
Jun-Young Oh 《International Journal of Science and Mathematics Education》2014,12(2):353-370
Constructing explanations and participating in argumentative discourse are seen as essential practices of scientific inquiry. The objective of this study was to explore the elements and origins of pre-service secondary science teachers’ alternative conceptions of tidal phenomena based on the elements used in Toulmin’s Argument Model through qualitative research. The data were collected from three pre-service secondary school teachers (D.-K. University, Teachers’ Colleges, junior and senior) in the Republic of Korea using a variety of qualitative research methods. We present three pre-service teachers as examples of 20 pre-service teachers for determining each pre-service teacher whether the pattern of his/her responses to all of the questions investigating a given concept can be explained by the consistent use of components of argument. The results of this study showed “the model with the Earth’s center at rest” backing their warrants as an element of Toulmin’s Argument Model. As a result, science educators must explicitly address these presuppositions or implicit beliefs and must help the students form links between their everyday experiences and scientific knowledge. Therefore, educators must be aware of the influence of students’ presuppositions and must use acceptable scientific concepts (the center of mass of the Earth–Moon system) based on argumentation to guide their construction of scientific concepts. 相似文献
85.
Linfeng Xu Hun Lee Mariana Vanderlei Brasil Pinheiro Phil Schneider Deekshitha Jetta Kwang W. Oh 《Biomicrofluidics》2015,9(1)
We propose a blood separation microfluidic device suitable for point-of-care (POC) applications. By utilizing the high gas permeability of polydimethylsiloxane (PDMS) and phaseguide structures, a simple blood separation device is presented. The device consists of two main parts. A separation chamber with the phaseguide structures, where a sample inlet, a tape-sealed outlet, and a dead-end ring channel are connected, and pneumatic chambers, in which manually operating syringes are plugged. The separation chamber and pneumatic chambers are isolated by a thin PDMS wall. By manually pulling out the plunger of the syringe, a negative pressure is instantaneously generated inside the pneumatic chamber. Due to the gas diffusion from the separation chamber to the neighboring pneumatic chamber through the thin permeable PDMS wall, low pressure can be generated, and then the whole blood at the sample inlets starts to be drawn into the separation chamber and separated through the phaseguide structures. Reversely, after removing the tape at the outlet and manually pushing in the plunger of the syringe, a positive pressure will be created which will cause the air to diffuse back into the ring channel, and therefore allow the separated plasma to be recovered at the outlet on demand. In this paper, we focused on the study of the plasma separation and associated design parameters, such as the PDMS wall thickness, the air permeable overlap area between the separation and pneumatic chambers, and the geometry of the phaseguides. The device required only 2 μl of whole blood but yielding approximately 0.38 μl of separated plasma within 12 min. Without any of the requirements of sophisticated equipment or dilution techniques, we can not only separate the plasma from the whole blood for on-chip analysis but also can push out only the separated plasma to the outlet for off-chip analysis. 相似文献
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87.
There has been increasing interest on the role of private foundations in education finance and delivery. We argue that this is due to a macro-policy context of stagnating levels of official development assistance for education and an uncritical acceptance of a logic of neutrality and the efficiency and effectiveness of of partnerships and philanthropy. This paper reports on the results of a literature review on private foundations in education and development. It found significant contestation against the claims of neutrality, efficiency, effectiveness. It also identifies salient methodological and substantive issues for the development of a research agenda on the issue. 相似文献
88.
As new venues of information and tools for information access are emerging, people's online information seeking behavior is dramatically evolving. While a majority of well-established and classical models of information seeking and behavior are still valid, there is a growing need to study and explain novel information sources and information seeking behaviors that are unique to these sources. One emerging domain is social question and answer (Q&A). This article develops a research agenda for social Q&A, reviewing recent studies and identifying core issues, questions, and challenges. 相似文献
89.
Seong Hwan Oh Andreas Mierau Mario Thevis Andreas Thomas Christoph Schneider Alexander Ferrauti 《Sportwissenschaft》2018,48(2):235-244
The aim of this study was to investigate the effect of two different exercise interventions in the morning on football-specific components of performance in the afternoon under conditions simulating a competition day. In the morning on 3 experimental days, 12 football players (age 24.1?±?5.5 years) completed three different preload interventions that were applied in a counter-balanced order: (1) no intervention (NI); (2) moderate-intensive exercise (MI); and (3) high-intensive exercise (HI). The subjects performed the preload exercises, consisting of a small-sided game and repeated maximal sprints, from 10:00–11:00 a.m. At 3:00 p.m., the Bangsbo test (BT) was applied to examine the effects of the different morning interventions on football-specific endurance capacity. The results showed that the HI led to significantly higher blood-lactate concentrations (moderate to very large effect) and heart rates (very large to extremely large effect) compared to the MI. In addition, there was a significant measurement?×?intervention effect on concentrations of adrenalin and noradrenalin in the urine, which reached higher values immediately after the HI (very large effect) and MI (moderate effect) compared to NI. All effects disappeared by the time of the BT in the afternoon. During all trials, after the preload intervention, reaction time and critical flicker fusion frequency increased significantly compared to the baseline morning values (reaction time: small; critical flicker fusion: trivial to small effect), but no measurement?×?intervention interaction was found. During the BT, the mean total distance covered (trivial to small effect) and the pacing pattern did not differ significantly among the trials despite numerous small individual effects. We conclude that exercise interventions of various intensities in the morning have no general effect on football-specific components of performance in the afternoon despite significant metabolic, endocrinological and cognitive short-term effects. Coaches should consider individual preferences when prescribing competition-day procedures. 相似文献
90.
Kangrok Oh Zhengguo Li Beom-Seok Oh Kar-Ann Toh 《Journal of The Franklin Institute》2018,355(4):1614-1637
In this paper, an optimization problem is formulated for stable binary classification. Essentially, the objective function seeks to optimize a full data transformation matrix along with the learning of a linear parametric model. The data transformation matrix and the weight parameter vector are alternatingly optimized based on the area above the receiver operating characteristic curve criterion. The proposed method improves the existing means via an optimal data transformation rather than that based on the diagonal, random and ad-hoc settings. This optimal transformation stretches beyond the fixed settings of known optimization methods. Extensive experiments using 34 binary classification data sets show that the proposed method can be more stable than competing classifiers. Specifically, the proposed method shows robustness to imbalanced and small training data sizes in terms of classification accuracy with statistical evidence. 相似文献