Perception of kinematic characteristics of tennis strokes for anticipating stroke type and direction     

Shim J  Les Carlton G  Kwon YH 《Research quarterly for exercise and sport》2006,77(3):326-339

The purpose of this study was to determine the sources of visual information used by highly skilled tennis players in anticipating their opponent's shots. In Experiment 1, motion analysis of the strokes showed that the relative motion between the racquet and forearm was different between the ground strokes and lobs, but there were no reliable kinematic differences when shot direction was varied. In Experiment 2, 12 skilled tennis players observed the opponent hitting strokes in a normal video or in a point-light display with different segments occluded. Players' anticipation accuracy was not degraded by the use of the point-light display. Occluding the racquet and forearm significantly reduced the participant's ability to determine the type of stroke produced.  相似文献   

The experience of professional autonomy among psychotherapists in Korea and the United States     

Sue Hyun Bae  David E. Orlinsky   《Int J Intercult Relat》2004,28(6):481-505

This study investigates professional autonomy as experienced by psychotherapists in Korea and in the United States using data collected as part of a collaborative international study of the development of psychotherapists (Orlinsky et al. (1999). Psychotherapy Research, 9(2), 127–153; Orlinsky & Rønnestad, (2005). How psychotherapists develop: A study of therapeutic work and professional growth. Washington, DC: American Psychological Association). The major aims are: to compare the extent of professional autonomy experienced by psychotherapists in Korea and by their counterparts in the USA; and to explore the professional and social correlates of the professional autonomy experienced by Korean therapists and compare these with the correlates of autonomy experienced by American therapists. These aims are pursued through analyses of a database of questionnaire responses. Results indicate that Korean therapists, compared to American therapists in our sample experience significantly lower levels of professional autonomy. For Korean therapists, whether they have a salient theoretical orientation in their practice is the single most important influence in their experience of work autonomy. Seniority and work setting are also significant correlates of autonomy for the Korean therapists. Similar to Korean therapists, seniority and having a salient orientation are also important influences on the way American therapists experience professional autonomy. American therapists, who work in independent practice experience higher work autonomy, whereas American social workers tend to experience lower professional autonomy.  相似文献   

Effects of light refraction on the accuracy of camera calibration and reconstruction in underwater motion analysis   总被引：1，自引：0，他引：1  

Kwon YH  Casebolt JB 《Sports biomechanics / International Society of Biomechanics in Sports》2006,5(2):315-340

One of the most serious obstacles to accurate quantification of the underwater motion of a swimmer's body is image deformation caused by refraction. Refraction occurs at the water-air interface plane (glass) owing to the density difference. Camera calibration-reconstruction algorithms commonly used in aquatic research do not have the capability to correct this refraction-induced nonlinear image deformation and produce large reconstruction errors. The aim of this paper is to provide a thorough review of: the nature of the refraction-induced image deformation and its behaviour in underwater object-space plane reconstruction; the intrinsic shortcomings of the Direct Linear Transformation (DLT) method in underwater motion analysis; experimental conditions that interact with refraction; and alternative algorithms and strategies that can be used to improve the calibration-reconstruction accuracy. Although it is impossible to remove the refraction error completely in conventional camera calibration-reconstruction methods, it is possible to improve the accuracy to some extent by manipulating experimental conditions or calibration frame characteristics. Alternative algorithms, such as the localized DLT and the double-plane method are also available for error reduction. The ultimate solution for the refraction problem is to develop underwater camera calibration and reconstruction algorithms that have the capability to correct refraction.  相似文献   

Social IEP Objectives, Teacher Talk, and Peer Interaction in Inclusive and Segregated Preschool Settings     

Kyong-Ah Kwon  James Elicker  Susan Kontos 《Early Childhood Education Journal》2011,39(4):267-277

The purpose of this study was to examine: (a) the role of teacher talk in promoting peer interaction, (b) the adequacy of social IEP objectives to reflect children’s social functioning and guide provision of teacher talk, and (c) differences in children’s peer interaction and teacher talk in inclusive and segregated settings. Thirty children with disabilities and their teachers participated. Overall, we observed low rates of teacher talk thought to support peer interaction; however, when teachers verbally facilitated peer interaction, children were observed interacting more frequently with peers. Children’s social IEPs accurately reflected their current level of social functioning. However, the social IEPs appeared to fail to influence teacher intervention. Finally, children with disabilities in inclusive settings interacted with peers more than children in segregated settings, even though there was no significant difference in amount of teacher talk in the two settings.  相似文献   

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

Hyun Jeong Kim  Gary Pan  Shan Ling Pan 《Government Information Quarterly》2007

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.  相似文献   

Public library patrons' use of collaborative chat reference service: The effectiveness of question answering by question type     

Nahyun Kwon 《Library & information science research》2007

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Identifying and removing duplicate records from systematic review searches     

Yoojin Kwon  Michelle Lemieux  Jill McTavish  Nadine Wathen 《Journal of the Medical Library Association》2015,103(4):184-188

Objective

The purpose of this study was to compare effectiveness of different options for de-duplicating records retrieved from systematic review searches.

Methods

Using the records from a published systematic review, five de-duplication options were compared. The time taken to de-duplicate in each option and the number of false positives (were deleted but should not have been) and false negatives (should have been deleted but were not) were recorded.

Results

The time for each option varied. The number of positive and false duplicates returned from each option also varied greatly.

Conclusion

The authors recommend different de-duplication options based on the skill level of the searcher and the purpose of de-duplication efforts.  相似文献   

The Effects of Perfectionism and Dispositional Self-focused Attention of Novice Counselor on Psychological Burnout: Moderated Mediating Effects of Cognitive Emotion Regulation Strategies     

Kwon  Wonju  Ha  Jung Hee  Jang  Hansori  Lee  Donghun 《International journal for the advancement of counseling》2022,44(2):283-297

International Journal for the Advancement of Counselling - The current study investigated the mediation effect of self-focused attention on the relationship between South Korean novice...  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   

An unexpected particle oscillation for electrophoresis in viscoelastic fluids through a microchannel constriction     

Xinyu Lu  Saurin Patel  Meng Zhang  Sang Woo Joo  Shizhi Qian  Amod Ogale  Xiangchun Xuan 《Biomicrofluidics》2014,8(2)

Electrophoresis plays an important role in many applications, which, however, has so far been extensively studied in Newtonian fluids only. This work presents the first experimental investigation of particle electrophoresis in viscoelastic polyethylene oxide (PEO) solutions through a microchannel constriction under pure DC electric fields. An oscillatory particle motion is observed in the constriction region, which is distinctly different from the particle behavior in a polymer-free Newtonian fluid. This stream-wise particle oscillation continues until a sufficient number of particles form a chain to pass through the constriction completely. It is speculated that such an unexpected particle oscillating phenomenon is a consequence of the competition between electrokinetic force and viscoelastic force induced in the constriction. The electric field magnitude, particle size, and PEO concentration are all found to positively affect this viscoelasticity-related particle oscillation due to their respective influences on the two forces.  相似文献