• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.813-824
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• 2010

Thermal conductivity of soils is one of the most important parameters to design horizontal ground heat exchangers. It is well known that the thermal conductivity of soil is strongly influenced by its density and water content because of soil's particulate structure. This paper reviewed and evaluated some of the commonly used prediction models for thermal conductivity of soils with the experimental data available in the literature. Semi-theoretical models for two-component materials were found inappropriate to estimate the thermal conductivity of dry state sands. It came out that the model developed by Cote and Konrad gave the best overall prediction for unsaturated sands available in the literature. Also, a parametric analysis is conducted to investigate the effect of thermal conductivity and water content, soil type on the horizontal ground heat exchanger design. The analysis shows that a required pipe length for the horizontal ground heat exchanger is reduced with the increase of soil thermal conductivity and water content. The calculation results also show that the dimension of the horizontal ground heat exchanger can be reduced to a certain extent by using backfilling material with a higher thermal conductivity of solid particles.

• Journal of Chest Surgery
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• v.46 no.2
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• pp.117-123
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• 2013

Background: We examined perioperative predictors of sustained sinus rhythm (SR) in patients undergoing the Cox maze operation and concomitant cardiac surgery for structural heart disease. Materials and Methods: From October 1999 to December 2008, 90 patients with atrial fibrillation (AF) underwent the Cox maze operation and other concomitant cardiac surgery. Eighty-nine patients, all except for one postoperative death, were followed-up with serial electrocardiographic studies, 24-hour Holter monitoring tests, and regular echocardiographic studies. Results: Eighty-nine patients undergoing the maze operation were divided into two groups according to the presence of SR. At the time of last follow-up (mean follow-up period, $51.0{\pm}30.8$ months), 79 patients (88.8%) showed SR (SR group) and 10 patients (11.2%) had recurrent AF (AF group). Factors predictive of sustained SR were the immediate postoperative conversion to SR (odds ratio, 97.2; p=0.001) and the presence of SR at the 6th month postoperatively (odds ratio, 155.7; p=0.002). Duration of AF, mitral valve surgery, number of valves undergoing surgery, left atrial dimension, and perioperative left ventricular dimensions and ejection fractions were not predictors of postoperative maintenance of SR. Conclusion: Immediate postoperative SR conversion and the presence of SR at the 6th postoperative month were independent predictors of sustained SR after the maze operation.

• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.7 s.155
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• pp.1012-1024
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• 2006

The purpose of this study is to investigate the effect of color, shirt tone, tie tone, perceiver's gender on impression formation by applying tone on tone coloration of shirt and necktie: coloration of two colors. The experimental materials developed for this study were a set of stimulus and response scales. The stimuli were 32 upper body photographs which were color outputs by CAD system(4D-box program). We unified those colors of shirts and neckties same, then made shirt and necktie tone differently. 27 bi-polar adjectives, each of which was graded into seven in its degree, were used to evaluate the impression. The subjects of this research were 192 male and 192 female college students in Gyeongnam province including Jinju City. The data was analyzed by using SPSS program. Analysis methods were four-way ANOVA. The items of the adjectives were classified into 5 impression dimension. - potency, activity, attractiveness, visibility and tenderness. Color, shirt tone, tie tone, and perceiver gender influenced on 5 impression formation by interaction as well as independently. Blue tie with vivid, light or dull tone had an effect on the formation of potency impression, vivid or light tone of shirt affected activity regardless of color or tie tone. As shirt and tie had different tone, effect on the formation of attractiveness impression, light tone had a negative effect on visibility but positive effect on tenderness. red color were more effective than blue expressed on visibility and tenderness in shirt or tie.

• The Journal of the Korea Contents Association
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• v.13 no.6
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• pp.77-85
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• 2013

This study aims to analyze the effects that video image in Seo-an's , claiming to China's first gigantic historic dance drama, has on the performance; it focuses on investigating which video image is used to accomplish the effects in showing specific themes and materials in . Image is meant by 'reflection of object', such as movie, television, dictionary, etc, with its coverage being extensive. The root of a word, image', is founded on imitary, signifying specifically and mentally visual representation. In other words, video image is considered combination of two synonymous words, 'video' and 'image'. Video is not just comprehension of traditional art genre, like literary value, theatrical qualities, and artistry of scenario, but wholeness as product, integrating original functions of all kinds of art and connecting subtle image creation of human being. The effects of video image represented in are as followings; first, expressive effect of the connotative meaning, reflecting the spirit of the age and its culture. Second, imaginary identification. Third, transformation scene. Fourth, dramatic interest through immersion. Last but not least, visual effect by dint of dimension of performance.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 1997.10a
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• pp.7-7
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• 1997

During sintering of very porous green bodies, as obtained by compaction of hard powders - such as tungsten carbide or ceramics - or by injection moulding, important shrinkage occurs. Due to heterogeneous green density field, gravity effects, friction on the support, thermal gradients, etc., this shrinkage is often non-uniform, which' may induce significant shape changes. As the ratio of compact dimension to powder size is very high, the mechanics of continuum is relevant to model such phenomena. Thus numerical techniques, such as the finite element method can be used to simulate the sintering process and predict the final shape of the sintered part. Such type of simulation has much been developed in the last decade firstly for hot isostatic pressing and next for die compaction. Finite element modelling has been recently applied to free sintering. The simulation of sintering should be based on constitutive equations describing the thermo-mechanical behaviour of the material under any state of stress and any temperature which may arise within the sintering body. These equations can be drawn either from experimental data or from micromechanical models. The experiments usually consist in free sintering and sinter-forging tests. Indeed applying more complex loading conditions at high temperature under controlled atmosphere is delicate. Micromechanical models describe the constitutive behaviour of aggregates of spheres from the deformation of two-sphere contact either by viscous flow or grain boundary diffusion. Such models are not able to describe complex microstructure and mechanisms as observed in real materials but they can give some basic information on the formulation of constitutive equations. Practically both experimental and theoretical approaches can be coupled to identify the constitutive equations. Such procedure has been performed for modelling the sintering of compacts obtained by die pressing of a mixture of tungsten carbide and cobalt powders. The constitutive behaviour of this material during sintering has been described by a linear viscous constitutive model, whose functions have been fitted from results of free sintering and sinter-forging experiments. This model has next been introduced in ABAQUS finite element code to simulate the sintering of heterogeneous green compacts of various geometries at constant temperature. Examples of simulations are shown and compared with experiments.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.23 no.1
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• pp.7-14
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• 2001

Purpose : The lateral cephalometric Korean norms of the skeletal and pharyngeal dimension were analyzed for the diagnosis of obstructive sleep apnea syndrome(OSAS). Materials and Methods : The lateral cephalometric radiographies were taken in male(n=53) and female(n=50), who had a normal profile, class I occlusion, normal ANB $(0{\sim}4^{\circ})$ and normal Wits $Appraisal(-4{\sim}0mm)$. The X-rays were traced by two oral and maxillofacial surgeons twice. The significant differences between male-female and examiners were tested. Results : The angle of mandibular line to Nasion-Sella line was $31.12^{\circ}/33.79^{\circ}$ (in male/in female, p=0.0018). The lower Gonion angle was $73.74^{\circ}/73.74^{\circ}(p=0.9978)$. The length of the soft palate was 36.93mm/34.35mm(p=0.0002). The pharyngeal airway space was 13.42mm/11.55mm at mandibular plane level(PAS(ML))(p=0.0025). The hyoid was placed inferiorly to mandibular plane 10.18mm/7.72mm(p=0.0051). The results from this study are to be used for the diagnosis of OSAS.

• Nuclear Engineering and Technology
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• v.52 no.4
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• pp.661-673
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• 2020

The quarter-core simulation of BEAVRS Cycle 2 depletion benchmark has been conducted using the MCS/CTF coupling system. MCS/CTF is a cycle-wise Picard iteration based inner-coupling code system, which couples sub-channel T/H (thermal/hydraulic) code CTF as a T/H solver in Monte Carlo neutron transport code MCS. This coupling code system has been previously applied in the BEAVRS benchmark Cycle 1 full-core simulation. The Cycle 2 depletion has been performed with T/H feedback based on the spent fuel materials composition pre-generated by the Cycle 1 depletion simulation using refueling capability of MCS code. Meanwhile, the MCS internal one-dimension T/H solver (MCS/TH1D) has been also applied in the simulation as the reference. In this paper, an analysis of the detailed criticality boron concentration and the axially integrated assembly-wise detector signals will be presented and compared with measured data based on the real operating physical conditions. Moreover, the MCS/CTF simulated results for neutronics and T/H parameters will be also compared to MCS/TH1D to figure out their difference, which proves the practical application of MCS into the BEAVRS benchmark two-cycle depletion simulations.

• Journal of the Korea Concrete Institute
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• v.25 no.5
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• pp.529-537
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• 2013

The aim of the current study is to develop a nonlinear isoparametric layered frame finite element (FE) analysis of FRP strengthened reinforced concrete (RC) beam or column members by a force-based FE formulation. In sections, concrete is modeled in the triaxial stress-strain relationship state and the FRP sheet is modeled as layered composite materials in two-dimension. The element stiffness matrix derived by the force-based FE has the force-interpolation functions without assuming the displacement shape functions. A lateral load test of RC column strengthened by GFRP sheets was analyzed by the developed force-based FE model. From comparative studies of the experimental and analysis results, it was shown to compare with the stiffness FE method that the force-based FE analysis could give more accurate predictions in the overall lateral load-deflection response as well as in nonlinear deformations and damages in the column plastic hinge region.

• The Research Journal of the Costume Culture
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• v.13 no.5 s.58
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• pp.804-818
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• 2005

The purpose of this study is to investigate the effect of tone-on-tone coloration on the visual images of traditional Korean dress. The materials in the experiment developed for this study were made up of various stimuli and the response scales for each stimulus. The stimuli were 48 color pictures with various combination of colors, in which the tones of jackets and skirts were manipulated by computer drawing. 24 bi-polar adjectives, each of which was graded into seven in its degree, were used to evaluate each image. The subjects were 576 female students in Jinju City. This experiment was based on the $3{\times}4{\times}4$ factorial designs: color (red, yellow and green), jacket tone (vivid, light, dull and dark) and skirt tone (vivid, light, dull and dark). The results of the study can be summarized as follows; Impression factor of the stimuli consisted of the 5 different dimensions - youthfullness and activity, attractiveness, gracefullness, visibility, and tenderness. The colors and the tone of jackets and skirts used in this experiment influenced 5 impression dimension by interaction of two valuables or working independently. Yellow and green with vivid or light tone had an effect on the formation of youth and activity image, and dark-light combination had an effect on the formation of attractiveness image. In case of green color, light tone of a jacket and vivid or dull tone of a skirt affected gracefulness, while yellow has no impact on visibility image regardless of skirt tone. Red and yellow with vivid or light tone were a factor to decide tenderness.

• Imaging Science in Dentistry
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• v.38 no.2
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• pp.81-87
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• 2008

Purpose: To investigate the relationship between 3D bone architectural parameters and direction-related elastic moduli of cancellous bone of mandibular condyle. Materials and Methods: Two micro-pigs (Micro-$pig^R$, PWG Genetics Korea) were used. Each pig was about 12 months old and weighing around 44 kg. 31 cylindrical bone specimen were obtained from cancellous bone of condyles for 3D analysis and measured by micro-computed tomography. Six parameters were trabecular thickness (Tb. Th), bone specific surface (BS/BV), percent bone volume (BV/TV), structure model index (SMI), degree of anisotropy (DA) and 3-dimensional fractal dimension (3DFD). Elastic moduli of three orthogonal directions (superior-inferior (SI), medial-lateral (ML), andterior-posterior (AP) direction) were calculated through finite element analysis. Results: Elastic modulus of superior-inferior direction was higher than those of other directions. Elastic moduli of 3 orthogonal directions showed different correlation with 3D architectural parameters. Elastic moduli of SI and ML directions showed significant strong to moderate correlation with BV/TV, SMI and 3DFD. Conclusion: Elastic modulus of cancellous bone of pig mandibular condyle was highest in the SI direction and it was supposed that the change into plate-like structure of trabeculae was mainly affected by increase of trabeculae of SI and ML directions.