• The Journal of the Korea Contents Association
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• v.15 no.7
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• pp.629-642
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• 2015

The aim of this study is to investigate the efficacy of pair/group work on the improvement of receptive and productive vocabulary knowledge. One hundred and twelve university students participated in the study and they were divided into three groups. Pair work group(n=42) performed three vocabulary activities in pairs as extra-class works, and Individual work group(n=38) did them alone. On the other hand, Group work group(n=32) did the activities in groups consisting of four or five people during the class. Data were collected from one pretest and two posttest scores. The results showed that collaborative group work was conducive to the growth of both receptive and productive vocabulary knowledge. In contrast, pair groups who do not work collaboratively gained least vocabulary knowledge among three groups. From collaborative group work, participants in higher proficiency levels made greater vocabulary gains than those at lower levels. Based on these results, pedagogical implications are discussed.

• Structural Engineering and Mechanics
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• v.52 no.2
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• pp.427-443
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• 2014

This paper presents detailed analysis of the internal forces of interior beam-column joints of reinforced concrete (RC) frames under seismic action, identifies critical joint sections, proposes consistent definitions of average joint shear stress and average joint shear strain, derives formulas for calculating average joint shear and joint torque, and reports simplified analysis of the effects of joint shear and torque on the flexural strengths of critical joint sections. Numerical results of internal joint forces and flexural strengths of critical joint sections are presented for a pair of concentric and eccentric interior connections extracted from a seismically designed RC frame. The results indicate that effects of joint shear and torque may reduce the column-to-beam flexural strength ratios to below unity and lead to "joint-yielding mechanism" for seismically designed interior connections. The information presented in this paper aims to provide some new insight into the seismic behavior of interior beam-column joints and form a preliminary basis for analyzing the complicated interaction of internal joint forces.

• Journal of Korea Society of Digital Industry and Information Management
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• v.11 no.3
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• pp.79-90
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• 2015

Multipath routing technique is recognized as one of the effective approaches to improve the reliability of data forwarding. However, the traditional multipath routing focuses only on how many paths are needed to ensure a desired reliability. For this purpose, the protocols construct additional paths and thus cause significant energy consumption. These problems have motivated the study for the energy-efficient and reliable data forwarding. Thus, this paper proposes an energy-efficient concurrent multipath routing protocol with a small number of paths based on interaction between paths. The interaction between paths helps to reinforce the multipath reliability by making efficient use of resources. The protocol selects several nodes located in the radio overlapped area between a pair of paths as bridge nodes for the path-interaction. In order to operate the bridge node efficiently, when the transmission failure has detected by overhearing at each path, it performs recovery transmission to recover the path failure. Simulation results show that proposed protocol is superior to the existing multipath protocols in terms of energy consumption and delivery reliability.

• Bulletin of the Korean Chemical Society
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• v.4 no.2
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• pp.87-91
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• 1983

Molecular dynamic method has been applied to a single polymer chain immersed in a solvent. The interactions for the pairs, of two solvent molecules (SS), of a chain element and a solvent molecules (CS), and of two non-neighbor chain elements (CC) are given by the Lennard-Jones potential, and the interaction between two bonded chain elements is given by a harmonic potential. We changed the CS interaction parameter ${\varepsilon}_{CS}$ to 0.5, 1.0 and 2.0 times of the SS interaction ${\varepsilon}_{SS}$. We calculated the pair correlation functions for the SS, CS, and CC pairs, end-to-end distance and radius of gyration with the varying ${\varepsilon}_{CS}$ parameters. The results showed that a phase separation occurs between the polymer and solvent in the 0.5 system where ${\varepsilon}_{CS}$ = 0.5 {\varepsilon}_{SS}$. The autocorrelation functions for end-to-end distance and radius of gyration were also calculated.

• The Journal of Korean Academy of Sensory Integration
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• v.16 no.1
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• pp.25-34
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• 2018

Objective : This study aims to figure out the effect that sensory integration group therapy has on the fine motor, social interaction and playfulness of preschool children with intellectual disability. Methods : Participants were four children from three to five years old who were diagnosed with intellectual disabilities and they participated in twelve sessions of sensory integration group therapy, sixty minutes per session and once a week. Sensory integration group therapy was composed of parallel and peer play-centered gross motor activities, art activities and sensory plays that were related to each theme. Erhardt Developmental Prehension Assessment (EDPA), Penn Interactive Peer Play Scale (PIPPS) and Test of Playfulness (ToP) were used to evaluate participants' fine motor, social interaction and playfulness before and after the intervention. Results of fine motor, social interaction and playfulness before and after the intervention were compared using Wilcoxon matched-pair signed rank test. Results : After sensory integration group therapy intervention, the fine motor skills of participants did not show significant increases, but social interaction and playfulness showed significant increases (p< .05). Conclusion : Although sensory integration group therapy with preschool children with intellectual disability did not show positive improvement in fine motor skills, it showed positive effect on social interaction and playfulness. Group sensory integration therapy might be an intervention approach for all children with disabilities.

• Bulletin of the Korean Chemical Society
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• v.24 no.1
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• pp.55-59
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• 2003

This work is focused on analyzing ion-pair interactions and showing the effect of solvent induced inter-atomic attractions in various dielectric environments. To estimate the stability of ion-pairs, SCI-PCM ab initio MO calculations were carried out. We show that the solvent-induced attraction or ‘cavitation' energy of the ion-pair interactions in solution that arises mainly from the stabilization of the water molecules by the generation of an electrostatic field. In fact, even the strong electrostatic interaction characteristic of ion-pair interactions in the gas phase cannot overcome the destabilization or reorganization of the water molecules around solute cavities that arise from cancellation of the electrostatic field. The solvent environment, possibly supplemented by some specific solvent molecules, may help place the solute molecule in a cavity whose surroundings are characterized by an infinite polarizable dielectric medium. This behavior suggests that hydrophobic residues at a protein surface could easily contact the side chains of other nearby residues through the solvent environment, instead of by direct intra-molecular interactions.

• The Journal of the Acoustical Society of Korea
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• v.27 no.4
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• pp.183-190
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• 2008

In this paper, radiation characteristics of the beating sound are analytically investigated on a slightly asymmetric cylindrical shell. The cylindrical shell isan efficient model to consider the beat characteristics of Korean bells. Slight asymmetry in Korean bells makes mode pair which has close frequency components and the interaction of each mode pair produces beating sound. Based on the analytical model, the radiated sound field is determined. Using the sound beat map, the beating sound vs. direction and distance is investigated. Finally, results of the theoretical method are compared with those of the boundary element method to verify the validity.

• Journal of the Ergonomics Society of Korea
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• v.29 no.6
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• pp.889-895
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• 2010

This study compared the effects of craniocervical flexion exercise with conservative cervical flexion exercise in workers with chronic neck pain. Subjects were randomly allocated to two groups: control (n=20) and experimental group (n=20), respectively. The conservative exercise for the control group consisted of cervical flexion exercise, whereas the experimental group performed a craniocervical flexion exercise. To compare the two groups, the visual analogue scale (VAS) for a pain, neck disability index (NDI) for a neck disability scale, and cross sectional area (CSA) of longus colli muscle using ultrasound image were assessed on pre-intervention, post-intervention, and 2 weeks follow-up. 2-way repeated ANOVA was used with Bonferroni post-hoc test. (1) There were significant main effects (within and between groups) (p<0.05) and interaction effect (p<0.05) in VAS. Post-hoc test revealed that there were significant differences in all pair-wise comparisons. (2) There were significant main effects (within and between groups) (p<0.05) and interaction effect (p<0.05) in NDI. Post-hoc test revealed that there were significant differences between pre-intervention and post-intervention, pre-intervention and 2 weeks follow-up. (3) There were significant main effects (within and between groups) (p<0.05) and interaction effect (p<0.05) in CSA of longus colli muscle. Post-hoc test revealed that there were significant differences in all pair-wise comparisons. The findings indicate that craniocervical flexion exercise are more effective for improving pain, neck disability, and CSA of longus colli muscle than cervical flexion exercise in workers with chronic neck pain.

• Journal of Mechanical Science and Technology
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• v.20 no.1
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• pp.147-157
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• 2006

This paper represents a numerical study of the flow field due to the interactions between a pair of vortices produced by vortex generators in a rectangular channel flow. In order to analyze longitudinal vortices induced by the vortex generators, the pseudo-compressibility method is introduced into the Reynolds-averaged Navier-Strokes equations of a 3-dimensional unsteady, incompressible viscous flow. A two-layer $k-{\epsilon}$ turbulence model is applied to a flat plate 3-dimensional turbulence boundary to predict the flow structure and turbulence characteristics of the vortices. The computational results predict accurately the vortex characteristics related to the flow field, the Reynolds shear stresses and turbulent kinetic energy. Also, in the prediction of skin friction characteristics the computational results are reasonably close to those of the experiment obtained from other researchers.

• Journal of Mechanical Science and Technology
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• v.15 no.5
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• pp.623-629
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• 2001

The PSC (Propagation of Surfaces under Curvature) algorithm is adapted to the simulation of a flame propagation in a premixed medium including the effect of volume expansion across the flame front due to exothermicity. The algorithm is further developed to incorporate the flame anchoring scheme. This methodology is successfully applied to numerically simulate the response of an anchored V-flame to two strong free stream vortices, in accord with experimental observations of a passage of Karman vortex street through a flame. The simulation predicts flame cusping when a strong vortex pair interacts with flame front. In other words, this algorithm handles merging and breaking of the flame front and provides an accurate calculation of the flame curvature which is needed for flame propagation computation and estimation of curvature-dependent flame speeds.