Optoelectrofluidic field separation based on light-intensity gradients     

Sanghyun Lee  Hyun Jin Park  Jin Sung Yoon    Kwan Hyoung Kang 《Biomicrofluidics》2010,4(3)

Optoelectrofluidic field separation (OEFS) of particles under light -intensity gradient (LIG) is reported, where the LIG illumination on the photoconductive layer converts the short-ranged dielectrophoresis (DEP) force to the long-ranged one. The long-ranged DEP force can compete with the hydrodynamic force by alternating current electro-osmosis (ACEO) over the entire illumination area for realizing effective field separation of particles. In the OEFS system, the codirectional illumination and observation induce the levitation effect, compensating the attenuation of the DEP force under LIG illumination by slightly floating particles from the surface. Results of the field separation and concentration of diverse particle pairs (0.82–16 μm) are well demonstrated, and conditions determining the critical radius and effective particle manipulation are discussed. The OEFS with codirectional LIG strategy could be a promising particle manipulation method in many applications where a rapid manipulation of biological cells and particles over the entire working area are of interest.  相似文献   

Dickens for All: Inclusive Approaches to Literature and Communication with People with Severe and Profound Learning Disabilities     

Keith Park 《British Journal of Special Education》1998,25(3):114-118

Keith Park, a teacher of children with visual impairment and learning disabilities with the Greenwich Visual Impairment Service, describes a series of multisensory interactive drama games re-telling the story of A Christmas Carol by Charles Dickens, following a discussion of the potential uses of literature with people with severe and profound learning disabilities.  相似文献   

Centrifugal multiplexing fixed-volume dispenser on a plastic lab-on-a-disk for parallel biochemical single-end-point assays     

Moonwoo La  Sang Min Park  Dong Sung Kim 《Biomicrofluidics》2015,9(1)

In this study, a multiple sample dispenser for precisely metered fixed volumes was successfully designed, fabricated, and fully characterized on a plastic centrifugal lab-on-a-disk (LOD) for parallel biochemical single-end-point assays. The dispenser, namely, a centrifugal multiplexing fixed-volume dispenser (C-MUFID) was designed with microfluidic structures based on the theoretical modeling about a centrifugal circumferential filling flow. The designed LODs were fabricated with a polystyrene substrate through micromachining and they were thermally bonded with a flat substrate. Furthermore, six parallel metering and dispensing assays were conducted at the same fixed-volume (1.27 μl) with a relative variation of ±0.02 μl. Moreover, the samples were metered and dispensed at different sub-volumes. To visualize the metering and dispensing performances, the C-MUFID was integrated with a serpentine micromixer during parallel centrifugal mixing tests. Parallel biochemical single-end-point assays were successfully conducted on the developed LOD using a standard serum with albumin, glucose, and total protein reagents. The developed LOD could be widely applied to various biochemical single-end-point assays which require different volume ratios of the sample and reagent by controlling the design of the C-MUFID. The proposed LOD is feasible for point-of-care diagnostics because of its mass-producible structures, reliable metering/dispensing performance, and parallel biochemical single-end-point assays, which can identify numerous biochemical.  相似文献   

Introducing novel approaches for examining the variability of individuals’ physical activity     

Alex V. Rowlands  Sjaan R. Gomersall  Catrine Tudor-Locke  David R. Bassett  Minsoo Kang  François Fraysse 《Journal of sports sciences》2015,33(5):457-466

Tudor-Locke and colleagues previously assessed steps/day for 1 year. The aim of this study was to use this data set to introduce a novel approach for the investigation of whether individual’s physical activity exhibits periodicity fluctuating round a mean and, if so, the degree of fluctuation and whether the mean changes over time. Twenty-three participants wore a pedometer for 365 days, recorded steps/day and whether the day was a workday. Fourier transform of each participant’s daily steps data showed the physical activity had a periodicity of 7 days in half of the participants, matching the periodicity of the workday pattern. Activity level remained stable in half of the participants, decreased in ten participants and increased in two. In conclusion, the 7-day periodicity of activity in half of the participants and correspondence with the workday pattern suggest a social or environmental influence. The novel analytical approach introduced herein allows the determination of the periodicity of activity, the degree of variability in activity that is tolerated during day-to-day life and whether the activity level is stable. Results from the use of these methodologies in larger data sets may enable a more focused approach to the design of interventions that aim to increase activity.  相似文献   

How liberals and conservatives respond to feasibility and desirability appeals in anti-tobacco campaigns     

Younghwa Lee  Sukki Yoon  Seungwoo Chun  Chanmo Park  Kacy Kim 《亚洲交流杂志》2019,29(1):55-72

Using two experiments, this study aims to investigate how politically liberal or conservative message recipients respond to anti-tobacco appeals. The results show that in Study 1, respondents were exposed to a message about price policy. In Study 2, they were exposed to a message about a warning policy. In both studies, liberal participants more favorably evaluated anti-tobacco messages emphasizing feasibility rather than desirability, whereas conservative participants more positively evaluated messages emphasizing desirability rather than feasibility. Implications for policymakers and marketers are discussed.  相似文献   

Exploring the International Student Experience: Providing Insight Through a Mixed-Methods Approach     

Melissa Burel  Marlee Graser  Sarah Park 《图书馆管理杂志》2019,59(2):149-174

Southern Illinois University Edwardsville (SIUE) has seen a dramatic increase in international student enrollment in the last four years. To serve this rising population effectively, librarians at SIUE created a research study to explore the information needs and academic experiences of international students at SIUE. The study employed a mixed-methods approach including a survey as well as in-depth interviews and photo diaries. The results provide insight into international students’ library use and academic life.  相似文献   

Learning Politics From Social Media: Interconnection of Social Media Use for Political News and Political Issue and Process Knowledge     

Chang Sup Park 《Communication Studies》2019,70(3):253-276

Drawing on a national survey of 1,157 South Korean adults, the present study finds that social media use for political news is positively associated with knowledge about political issues, but not with knowledge about political processes. Professional media use for political news is significantly associated with both political issue knowledge and political process knowledge. The impact of social media for news on political issue knowledge increases with the additive role of professional media news use. This study also finds that political talk strengthens the positive association between social media use for news and political issue knowledge.  相似文献   

Examining the Legacy of Urban Catholic Schooling in the U.S.: A Systematic Literature Review     

Miller  Andrew F.  Park  Younghee  Conway  Patrick  Cownie  Charles T.  Reyes  John  Reynoso  Myra  Smith  Annie 《The Urban Review》2022,54(3):481-508

The Urban Review - Research conducted in the twentieth century found urban Catholic schools in the U.S. had a legacy of providing high quality educational opportunities for low-income students and...  相似文献   

Spectral clustering with physical intuition on spring–mass dynamics     

Jinho Park  Moongu Jeon  Witold Pedrycz 《Journal of The Franklin Institute》2014

In this paper, we provide a new insight into clustering with a spring–mass dynamics, and propose a resulting hierarchical clustering algorithm. To realize the spectral graph partitioning as clustering, we model a weighted graph of a data set as a mass–spring dynamical system, where we regard a cluster as an oscillating single entity of a data set with similar properties. And then, we describe how oscillation modes are related with eigenvectors of a graph Laplacian matrix of the data set. In each step of the clustering, we select a group of clusters, which has the biggest number of constituent clusters. This group is divided into sub-clusters by examining an eigenvector minimizing a cost function, which is formed in such a way that subdivided clusters will be balanced with large size. To find k clusters out of non-spherical or complex data, we first transform the data into spherical clusters located on the unit sphere positioned in the (k−1)-dimensional space. In the sequel, we use the previous procedure to these transformed data. The computational experiments demonstrate that the proposed method works quite well on a variety of data sets, although its performance degrades with the degree of overlapping of data sets.  相似文献   

Synchronization of discrete-time complex dynamical networks with interval time-varying delays via non-fragile controller with randomly occurring perturbation     

M.J. Park  O.M. Kwon  Ju H. Park  S.M. Lee  E.J. Cha 《Journal of The Franklin Institute》2014

This paper addresses synchronization problem for discrete-time complex dynamical networks with interval time-varying delays. In order to achieve the synchronization, a feedback controller subjected to randomly occurring perturbations will be considered. The randomly occurring perturbations are assumed to belong to the Binomial sequence. By constructing a suitable Lyapunov–Krasovskii functional, and utilizing reciprocally convex approach and Finsler?s lemma, the synchronization criteria for the networks are established in terms of linear matrix inequalities (LMIs) which can be easily solved by various effective optimization algorithms. The networks are represented by the use of Kronecker product technique. The effectiveness of the proposed methods will be verified via numerical examples.  相似文献