• The Journal of Engineering Geology
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• v.8 no.3
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• pp.215-224
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• 1998

In this study, total strain was measured by LVDTs and local strains on the surface of specimens were measured by strain gauges. And axi-symmetrically elastoplastic FEM analyses was carried out for cylindrical specimens. Considering the influence of the restraint induced by the loading platen, in the case of H/D=1, the strain distribution on the side of a specimen is obviously affected by the condition of platen contact. Furthermore, it is clear that the larger H/D ratio becomes, the smaller the influence to the strain distribution is. For the smooth contact condition, the strain on the side is not influenced by the stiffness of the specimen, the shape and the scale effect, the strain distribution coincides with the nominal total strain. Whereas, in the case of rough contact condition, the strain distribution is remarkably affected. It is made clear that strain responses of hard rock specimens may more sensitive than these of soft rock specimens as a results of interaction between loading platens and specimen and the uniaxial strength of specimens may strongly depends on this interaction and stress-strain relation is affected by the contact condition.

• Journal of the Korean Geotechnical Society
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• v.37 no.12
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• pp.25-31
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• 2021

Boundary conditions for thermal-hydraulic problems of soils play an essential role in the numerical accuracy. This study presents a boundary condition considering the thermo-hydraulic interaction between the ground and the atmosphere. Ground surface energy balance consists of solar radiation, ground radiation, wind convection, latent heat from water evaporation, and heat conduction to the ground. Equations for each heat flux are presented, and numerical analyses are performed in conjunction with the FEM program for the thermal-hydraulic phenomenon of unsaturated soils. Numerical results using the weather data at the Ulsan Meteorological Observatory are similar to the measured surface temperature. Latent heat caused by water evaporation during the daytime lowers the surface temperature of the bare soil, and a thermal equilibrium is reached at nighttime when the effect of the ground condition is significantly reduced. The temperature change of the surface ground is diminished at the deeper ground due to its thermal diffusion. Numerical analysis where the surface ground temperature is the primary concern requires considering the thermo-hydraulic interaction between the ground and the atmosphere.

• Journal of Periodontal and Implant Science
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• v.32 no.1
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• pp.129-142
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• 2002

Epithelial-mesenchymal interaction plays a important role in cell growth and differentiation. This interaction is already well known to have an importance during the organ development as well as cell growth and differentiation. However, in vitro experimental model is not well developed to reproduce in vivo cellular microenvironment which provide a epithelial-mesenchymal interaction. Because conventional monolayer culture lacks epithelial-mensenchymal interaction, cultivated cells have an morphologic, biochemical, and functional characteristics differ from in vivo tissue. Moreover, it's condition is not able to induce cellular differention due to submerged culture condition. Therefore, the aims of this study were to develop and evaualte the in vitro experimental model that maintains epithelial-mesenchymal interaction by organotypic raft culture, and to characterize biologic properties of three-dimensionally reconstituted oral keratinocytes by histological and immunohistochemical analysis. The results were as follow; 1. Gingival keratinocytes reconstituted by three-dimensional organotypic culture revealed similar morphologic characteristics to biopsied patient specimen showing stratification, hyperkeratinosis, matutation of epithelial architecture. 2. Connective tissue structure was matured, and there is no difference during stratification period of epithelial 3-dimensional culture. 3. The longer of air-exposure culture on three-dimensionally reconstituted cells, the more epithelial maturation, increased epithelial thickness and surface keratinization 4. In reconstitued mucosa, the whole epidermis was positively stained by anti-involucrin antibody, and there is no difference according to air-exposured culture period. 5. The Hsp was expressed in the epithelial layer of three-dimensionally cultured cells, especially basal layer of epidermis. The change of Hsp expression was not significant by culture stratification. 6. Connexin 43, marker of cell-cell communication was revealed mild immunodeposition in reconstitued epithelium, and there is no significant expression change during stratification. These results suggest that three-dimensional oragnotypic co-culture of normal gingival keratinocytes with dermal equivalent consisting type I collagen and gingival fibroblasts results in similar morphologic and immunohistochemical characteristics to in vivo patient specimens. And this culture system seems to provide adequate micro-environment for in vitro tissue reconstitution. Therefore, further study will be focused to study of in vitro gingivitis model, development of novel perioodntal disease therapeutics and epithelial-mensenchymal interaction.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2010.05a
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• pp.254-255
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• 2010

• 제어로봇시스템학회:학술대회논문집
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• 1987.10b
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• pp.209-213
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• 1987

This paper presents decentralized discrete-time system which is optimized by hierarchical control for process automation via the extended interaction balance method. This proposed method can control general matrix which input matrix is not block diagonalization. Also, this paper shows convergence condition of proposed method.

• Proceedings of the Korean Society for Bioinformatics Conference
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• 2001.08a
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• pp.103-127
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• 2001

Gene expression studies require statistical experimental designs and validation before laboratory confirmation. Various clustering approaches, such as hierarchical, Kmeans, SOM are commonly used for unsupervised learning in gene expression data. Several classification methods, such as gene voting, SVM, or discriminant analysis are used for supervised lerning, where well-defined response classification is possible. Estimating gene-condition interaction effects require advanced, computationally-intensive statistical approaches.

• Korean Journal of Cognitive Science
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• v.17 no.1
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• pp.29-52
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• 2006

There has been a claim that Interaction between the cerebral hemispheres could reduce the effect interfering information (Weissman & Banich, 1999). We ran three experiments to show that between-hemisphere separation of target and distractor could be more effective for reducing interference than Interaction between the hemispheres. In experiment 1, a colored box and a rotor name were presented to a single or to separate hemispheres. In experiment 2 and 3, a colored circle (distractor) was presented along with a colored box and a color name which was always printed in black. In experiment 3, a peripheral cue was presented either to the target location(66.7%) or to the distractor location(33.3%) Immediately before the presentation of stimuli. In all experiments, the participants were asked to deride whether the moaning of the color matched the rotor of the box, Ignoring the printed rotor of the word(Exp. 1), or the color of the circle(Exp. 2 & 3). There were three renditions of distractor (congruent, incongruent, and neutral) and two conditions of matching (between- and within-hemisphere matching). If interhemispheric interaction were effective for interference reduction, there should be a decrease in the interference in the between-hemisphere compared to the within-hemisphere matching condition. The results showed that there was no difference in the interference between the two matching conditions in Exp 1. In Exp 2 and in the target-cue renditions of Exp. 3, the amount of interference in the between-hemisphere condition was greater than that in the within-hemisphere condition. These findings are consistent with what we have previously reported (Sohn et al., 1996, Sohn & Lee, 2003). However, when the distractor was precued in Exp. 3, the amount of interference did not differ between the two marching conditions. These results suggest that between-hemisphere separation of target and distractor can be more effective for reducing response interference than interhemispheric communication. It implies a possible role of an interhemispheric shielding mechanism (Merola & Liederman, 1985) to prevent the transfer of task-irrelevant, harmful information across the hemispheres.

• Journal of the Ergonomics Society of Korea
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• v.35 no.6
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• pp.551-568
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• 2016

Objective: The objective of this study is to identify the difference in the press behavior characteristics of 3D Touch, which is a new touch interaction of smart phones, and the existing 'Tap and Long Press' touch interaction, and to examine behavior changes upon feedbacks. Background: Since 3D Touch is similar to the existing 'Tap and Long Press' touch interactions in terms of press behavior, which is likely to cause interference, it is necessary to conduct a preliminary study on behavior characteristics of touch interactions. Method: In utilization of smart phones with the 3D Touch function to measure press behavior characteristics of touch interaction, an experiment was conducted where 30 subjects were given a task to press 30 buttons of touch interactions on the screen. During the experiment, two press behavior characteristics-maximum touch pressure and press duration-were analyzed. To grasp changes in behaviors upon feedbacks, the task was carried out in a condition where there was no feedback and in a condition where there were feedbacks of specific critical values. Results: While there was no feedback given, subjects tended to press with much strength (318.98gf, 0.60sec) in the case of 3D Touch, and press the Long Press button for a while (157.12gf, 1.10sec) and press the Tap button with little strength only for a short moment (37.92gf, 0.10sec). 3D Touch and Long Press had an area of intersection in time, but when feedbacks of specific critical values were given, there were behavior calibration effects to adjust the press behavior characteristics of 3D Touch and Long Press. Conclusion: Although interferences are expected between 3D Touch and Long Press due to the similarity of press behaviors, feedbacks induce behavior calibration. Hence, once feedbacks were provided with 3D Touch operated in an appropriate condition of critical pressure, interference between two motions can be minimized. Application: The findings of this study are expected to be utilized as a basis for the values of optimal critical pressure, at which users can easily distinguish 3D Touch from Long Press which is the existing touch interaction.

• Korean Journal of Computational Design and Engineering
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• v.21 no.1
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• pp.20-30
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• 2016

Recently immersive virtual reality (VR) becomes popular due to the advanced development of I/O interfaces and related SWs for effectively constructing VR environments. In particular, natural and intuitive manipulation of 3D virtual objects is still considered as one of the most important user interaction issues. This paper presents a comparative study on the manipulation and interaction of 3D virtual objects using different interfaces and interactions in three VR environments. The comparative study includes both quantitative and qualitative aspects. Three different experimental setups are 1) typical desktop-based VR using mouse and keyboard, 2) hand gesture-supported desktop VR using a Leap Motion sensor, and 3) immersive VR by wearing an HMD with hand gesture interaction using a Leap Motion sensor. In the desktop VR with hand gestures, the Leap Motion sensor is put on the desk. On the other hand, in the immersive VR, the sensor is mounted on the HMD so that the user can manipulate virtual objects in the front of the HMD. For the quantitative analysis, a task completion time and success rate were measured. Experimental tasks require complex 3D transformation such as simultaneous 3D translation and 3D rotation. For the qualitative analysis, various factors relating to user experience such as ease of use, natural interaction, and stressfulness were evaluated. The qualitative and quantitative analyses show that the immersive VR with the natural hand gesture provides more intuitive and natural interactions, supports fast and effective performance on task completion, but causes stressful condition.

• Wind and Structures
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• v.20 no.2
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• pp.143-168
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• 2015

A numerical model for analyzing air-train-track interaction is proposed to investigate the dynamic behavior of a high-speed train running on a track in crosswinds. The model is composed of a train-track interaction model and a train-air interaction model. The train-track interaction model is built on the basis of the vehicle-track coupled dynamics theory. The train-air interaction model is developed based on the train aerodynamics, in which the Arbitrary Lagrangian-Eulerian (ALE) method is employed to deal with the dynamic boundary between the train and the air. Based on the air-train-track model, characteristics of flow structure around a high-speed train are described and the dynamic behavior of the high-speed train running on track in crosswinds is investigated. Results show that the dynamic indices of the head car are larger than those of other cars in crosswinds. From the viewpoint of dynamic safety evaluation, the running safety of the train in crosswinds is basically controlled by the head car. Compared with the generally used assessment indices of running safety such as the derailment coefficient and the wheel-load reduction ratio, the overturning coefficient will overestimate the running safety of a train on a track under crosswind condition. It is suggested to use the wheel-load reduction ratio and the lateral wheel-rail force as the dominant safety assessment indices when high-speed trains run in crosswinds.