• Structural Engineering and Mechanics
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• v.66 no.3
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• pp.329-341
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• 2018

This paper considers the smooth receding contact problem between a homogeneous half-plane and a composite laminate composed of an inhomogeneously coated elastic layer. The inhomogeneity of the elastic modulus of the coating is approximated by an exponential function along the thickness dimension. The three-component structure is pressed together by either a concentrated force or uniform pressures applied at the top surface of the composite laminate. Both semianalytical and finite element analysis are performed to solve for the extent of contact and the contact pressure. In the semianalytical formulation, Fourier integral transformation of governing equations and boundary conditions leads to a singular integral equation of Cauchy-type, which can be numerically integrated by Gauss-Chebyshev quadrature to a desired degree of accuracy. In the finite element modeling, the functionally graded coating is divided into homogeneous sublayers and the shear modulus of each sublayer is assigned at its lower boundary following the predefined exponential variation. In postprocessing, the stresses of any node belonging to sublayer interfaces are averaged over its surrounding elements. The results obtained from the semianalytical analysis are successfully validated against literature results and those of the finite element modeling. Extensive parametric studies suggest the practicability of optimizing the receding contact peak stress and the extent of contact in multilayered structures by the introduction of functionally graded coatings.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.143.1-143.1
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• 2012

We attempt to investigate the main reason of the asymmetrical light curves of contact and near-contact eclipsing binary base on the hypothesis that cool spot was produced on late type star while hot spot was produced from transferred material from their companion star hitting surface. We select 7 eclipsing binary systems which showed asymmetric light curves and mass transfer. Period variation and mass transfer rate were obtained from O-C diagram. Radial velocity curves and light curves of those 7 eclipsing binary system were adopted from available literature in order to obtain the absolute dimension. For four contact eclipsing binary system (AD Phe, EZ Hya, AG Vir and VW Boo), their component stars belonged to spectral type G to K was fitted by cool spot model. While the other two near-contact systems (RT Scl and V1010 Oph) and one contact system (SV Cen) was fitted by cool spot model. The densities of the materials are adopted from stellar model which calculate by stellar structure code. The calculated spot temperature turns out to agree with the photometric solution but there are no correlate between period variation rate and type of spot.

• Tribology and Lubricants
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• v.30 no.6
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• pp.378-383
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• 2014

This study predicts the of the hysteretic friction of a rubber block sliding on an SMA asphalt road. The friction of filled rubber on a rough surface is primarily determined by two elements:the viscoelasticity of the rubber and the multi-scale perspective asperities of the road. The surface asperities of the substrate exert osillating forces on the rubber surface leading to energy dissipation via the internal friction of the rubber when rubber slides on a hard and rough substrate. This study defines the power spectra at different length scales by using a high-resolution surface profilometer, and uses rubber and road surface samples to conduct friction tests. I consider in detail the case when the substrate surface has a self affine fractal structure. The theory developed by Persson is applied to describe these tests through comparison with the hysteretic friction coefficient relevant to the energy dissipation of the viscoelastic rubber attributable to cyclic deformation. The results showed differences in the absolute values of predicted and measured friction, but with high correlation between these values. Hence, the friction prediction model is an appropriate tool for separating the effects of each factor. Therefore, this model will contribute to clearer understanding of the fundamental principles of rubber friction.

• Journal of the Optical Society of Korea
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• v.15 no.1
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• pp.82-89
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• 2011

In this paper, we numerically study both band-pass and band-stop plasmonic filters based on Metal-Insulator-Metal (MIM) waveguides and circular ring resonators. The band-pass filter consists of two MIM waveguides coupled to each other by a circular ring resonator. The band-stop filter is made up of an MIM waveguide coupled laterally to a circular ring resonator. The propagating modes of Surface Plasmon Polaritons (SPPs) are studied in these structures. By substituting a portion of the ring core with air, while the outer dimensions of the ring resonator are kept constant, we illustrate the possibility of red-shift in resonant wavelengths in order to tune the resonance modes of the proposed filters. This feature is useful for integrated circuits in which we have limitations on the outer dimensions of the filter structure and it is not possible to enlarge the dimension of the ring resonator to reach to longer resonant wavelengths. The results are obtained by a 2D finite-difference time-domain (FDTD) method. The introduced structures have potential applications in plasmonic integrated circuits and can be simply fabricated.

• Journal of IKEEE
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• v.23 no.3
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• pp.793-799
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• 2019

In this study, the diffusion process and the thermal energy distribution gradient of the sensor were confirmed by using the finite element analysis program (COMSOL) of the mesh method to analyze the thermal diffusion in the wearable fabric (Nylon) + MWCNT gas sensor. To analyze the diffusion process of thermal energy, the structure of the gas sensor was modeled in a two dimension plane. The proposed modeling was presented with the characteristic value for the component of the sensor, and the gas sensor designed using the mesh finite element method (FEM) was proposed and analyzed by suggesting the one-way partial differential equation in the governing equation to know the degree of thermal energy diffusion and the thermal energy gradient. In addition, the temperature gradient 10[K/mm] of the anode-cathode electrode layer and the gas detection unit was investigated by suggesting the heat velocity transfer equation.

• Science of Emotion and Sensibility
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• v.24 no.3
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• pp.71-80
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• 2021

Previous studies using facial expressions have revealed valence and arousal as two core dimensions of affective space. However, it remains unknown if the two dimensional structure is consistent across ages. This study investigated affective dimensions using six facial expressions (angry, disgusted, fearful, happy, neutral, and sad) at three ages (young, middle-aged, and old). Several studies previously required participants to directly rate subjective similarity between facial expression pairs. In this study, we collected indirect measures by asking participants to decide if a pair of two stimuli conveyed the same emotions. Multidimensional scaling showed that "angry-disgusted" and "sad-disgusted" pairs are similar at all three ages. In addition, "angry-sad," "angry-neutral," "neutral-sad," and "disgusted-fearful" pairs were similar at old age. When two faces in a pair reflect the same emotion, "sad" was the most inaccurate in old age, suggesting that the ability to recognize "sad" decreases with old age. This study suggested that the general two-core dimension structure is robust across all age groups with the exception of specific emotions.

• Korean Journal of Cognitive Science
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• v.14 no.1
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• pp.41-50
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• 2003

We tested the capability of the pleasure and arousal dimension-based facial expression synthesis system and proposed the most effective interface for it. First, we tried to confirm the adequateness of the dimensional model as a basic structure of the internal states for the system. Fer it, subjects compared the 17 facial expressions on the two axes. The results validated the fundamental hypothesis of the system. Second, we chose 21 representative expressions from the system to test its performance and had subjects rate their similarities. We analyzed these data using multidimensional scaling methods and these results verified the system's reliability. Third, we compared the efficiencies of two interfaces -coordinate values and slide bars- to find the most suitable interface for the system. Subjects synthesise 25 facial expressions with each interface of it. The results showed that the visualization of two dimensional values into Cartesian coordinate is more stable as an input display of facial expression synthesis system based on dimensions.

• Journal of KIISE:Computing Practices and Letters
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• v.10 no.5
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• pp.406-418
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• 2004

Last days, various kinds of applications and system were individually introduced into specific groups or enterprises by different objective without considering interoperability among those. However, the environment for data processing is changing rapidly in these days. And now the necessity is growing to integrate and couple applications and system in the process dimension for more flexible and quicker data processing on these application programs and system. When integrating these application programs or system, an integration based on XML is recommended as it is one of good methods which will the additional cost and satisfy the requirements of the integration. This is because the XML is not only device-independent data type which can be used any platform, but also it uses XSLT, the document conversion standard established by W3C, which allows easy data conversion from one to another type on occasion of demands. This paper studies a design and implementation of system to convert XML structure. This system shows the structure of source- side providing data and destination-side processing data with using XML schema that defines structural information of a XML document. And this system defines the structure relationship of desired form as mapping structural information and data. This system creates the XSLT document that defines conversion rule between two structures based information which is defined. The XSLT document which is created as described above will convert data to be appropriate to the structure of the destination- side. By implementing this system, it is able to apply a document into various kinds of structure without considering specific system or platform and it is able to construct XSLT document to which meaning of desired form can be given. This paper aims to offer a process conversion between documents and to improve interoperability and scalability, so that we can contribute to build XML document processing environment

• Journal of the HCI Society of Korea
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• v.2 no.1
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• pp.13-24
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• 2007

For many years, human-computer interaction (HCI) practitioners have focused on usability in order to enhance the user experience, and companies have seen it as an area where they can gain advantages over their competitors. However, a focus on usability limits the potential of HCI research because it restricts the concept of user experience to just an implemented functionality of the information technology (IT). Therefore, it is necessary to expand the boundary of user experience research into a holistic dimension. We suggest that one of the most powerful ways to broadly understand user experience with an IT is to investigate the attributes of an IT and users' perceived values and to construct a user experience structure, a hierarchical structure between the attributes of an IT and users' perceived values. This study thus undertakes two research tasks: to develop a specific methodology, which is the visual probing, for constructing a user experience structure with the attributes of an IT and users' perceived values, and then to build a user experience structure practically by conducting a case study to a specific IT: mobile data service.

• Journal of the Korean Society of Earth Science Education
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• v.15 no.1
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• pp.76-90
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• 2022

In this study, after applying the argument structure class design program for 20 preservice earth science teachers, we conducted individual in-depth interviews, analyzed the data, and derived a scientific argumentation PCK development model. The scientific argumentation PCK development model consists of three dimensions: Scientific argumentation PCK, PCK ecosystem, and reflective practice. Scientific argumentation PCK is demonstrated in the process of designing or executing classes using argumentation structures as an instructional reasoning tool. PCK ecosystem, consisting of the existing conventional PCK components, is a dimension surrounding the scientific argumentation PCK, and these two dimensions develop by interacting with each other. Reflective practice regulates each dimension and develops it in various ways by mediating the two dimensions of the scientific argumentation PCK and the PCK ecosystem. The conclusions drawn based on the results are as follows: First, preservice science teachers can demonstrate scientific argumentation PCK in the process of design and implementation of lessons using argumentation structures as a pedagogical reasoning tool. Second, it is necessary to develop the PCK for pedagogical reasoning tools such as scientific argumentation PCK in advance for the development of science teachers' PCK, since the scientific argumentation PCK can develop various components of the PCK ecosystem. Finally, it is necessary to use scientific argumentation PCK to support the preservice teacher's reflective practice, seeing that the scientific argumentation PCK promotes the development of PCK ecosystem components by inducing reflective practice.