• Journal of the Korean Ceramic Society
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• v.50 no.3
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• pp.206-211
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• 2013

The effect of a $WO_3$ or $Ga_2O_3$ addition on the densification, phase evolution, optical reflectance, and elastic and dielectric properties of $Y_2O_3$-doped AlN ceramics sintered at $1800^{\circ}C$ for 3 h is investigated. The investigated compositions of the additives are 4.5 wt% $Y_2O_3$ (YA), 3.5 wt% $Y_2O_3$-1.0 wt% $Ga_2O_3$ (YGA), and 3.5 wt% $Y_2O_3$-1.0 wt% $WO_3$ (YWA). $YAlO_3$ and $Y_4Al_2O_9$ form as the secondary phases in all of the investigated compositions, whereas $W_2B$ appears additionally in the YWA. In the YGA, Ga is detected in the AlN grains, indicating that the dissolution of $Ga_2O_3$ into the AlN lattice occurs. The addition of $WO_3$ blackens the specimen more significantly than that of $Ga_2O_3$ does. In all of the investigated specimens, the linear shrinkage and the apparent density are above 20 percent and in the range of 3.34-3.37 $g/cm^3$, respectively. The elastic modulus, Poisson's ratio, the dielectric constant, and the dielectric loss are in the ranges of 335-368 GPa, 0.146-0.237, 8.60-8.63, $2.65-3.95{\times}10^{-3}$, respectively. The sinterability and the properties of $Y_2O_3$-doped AlN ceramics are not much altered by the addition of $WO_3$ or $Ga_2O_3$.

• The Korean Journal of Food And Nutrition
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• v.17 no.2
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• pp.111-119
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• 2004

A new type of drinkable yoghurt was prepared to develop a functional yoghurt. Skim milk containing 0.4-1.0％(w/v) water extract of omija(Schizandra chinensis Baillon) was fermented by the mixed strains of Lactobacillus acidophilus and Streptococcus thermophilus. Quality characteristics of the drinkable yoghurts were evaluated in terms of compositions, keeping-quality(pH, titratable acidity, number of viable cells) and sensory properties. The drinkable yoghurts added with water extract of Schizandra chinensis were composed of 2.92-3.03％ protein, 9.98-10.23％ lactose, 0.81-1.08％ fat, 16.21-16.64％ total solid, and 14.57-15.17％ solid-not-fat. The L values(brightness) were significantly lower in the yoghurts containing water extract of Schizandra chinensis than that of the control which had no water extract of Schizandra chinensis, while the a values(redness) and b values(yellowness) were significantly higher than those of the control. The pH, titratable acidity and number of viable cells of the lactic acid bacteria of all yoghurts were not changed during the storage at 4$^{\circ}C$ for 15 days, while the pH and titratable acidity were remarkedly changed during the yoghurts stored at 20$^{\circ}C$ for 15 days. The drinkable yoghurts containing 0.4％(w/v) water extract of Schizandra chinensis added 15％(w/v) oligosaccharide, or 0.6％(w/v) water extract of Schizandra chinensis added 20％(w/v) oligosaccharide had the highest sensory score in taste and overall acceptability among the treatments. From the results, Schizandra chinensis was a useful natural additive with the bioactive effect by provision of a acceptable physicochemical and sensory properties in the drinkable yoghurt.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.2
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• pp.116-129
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• 2005

Distraction osteogenesis is a new bone formation technique. There is a advantage of the environmental adaptation when distraction force is applied to the gap between osteotomy lines. But it has a disadvantage of long-term wearing of the appliance and long consolidation period. Therefore we make an effort to reduce it and repair normal function. Extracellular matrix proteins have a function to control the cellular growth, migration, shape and metabolism. In these, hyaluronic acid is a member of polysaccharide glycosaminoglycans (GAGs) and has a important function as bone formation and osteoinduction property. Purpose : In this experimental study in rabbit mandibular distraction osteogenesis, we investigated the bone enhancing property of hyaluronic acid and the expression of extracellular proteins such as osteocalcin and osteonectin. Materials and Methods : The experimental study was carried out on 24 Korean male white rabbits (both mandibular body, n=48). Distraction group was divided to distraction experimental (A, n=16) and distraction control (B, n=16) by the application of hyaluronic acid (Hyruan, LGCI, Seoul, Korea). Normal control group (C, n=16) was only osteotomized. After 5 days latency, distraction devices were activated at a rate of 1.4 mm per day (0.7 mm every 12hours) for 3.5 days. Animals were sacrificed at postoperative 3, 7, 14, and 28 days. H&E stain and immunohistochemical stain was done on decalcified section. Additionally RT-PCR analysis was done for the identification of the expression of osteocalcin and osteonectin. Results : The bone formation in distraction experimental group was much more than that in distraction and normal control group at postoperative 28 days. In immunohistochemical stain, osteocalcin was enhanced at only postoperative 14 days, but osteonectin was not different at each post-operation days. In RT-PCR analysis, osteocalcin was not different at each post-operation days, but osteonectin was strongly expressed in distraction experimental group at postoperative 7 days. The expression of osteocalcin and osteonectin was elevated during the healing period. Conclusion : We found the good bone formation ability of hyaluronic acid in distraction osteogenesis through the immunohistochemistry and RTPCR analysis to osteocalcin and osteonectin, known as a bone formation marker. The application of hyaluronic acid in distraction osteogenesis is a method to reduce the consolidation period.

• Journal of Information Technology Applications and Management
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• v.16 no.2
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• pp.1-21
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• 2009

The balanced scorecard(BSC) framework is a tool for strategic decision making and task support that aims for efficiency in performance management and strategy execution. BSC evolved from an old performance management practice, which tended to be limited to a finance-only perspective, to a new system of corporate management looking at corporate tasks from a multi-dimensional, future-inclined value perspective. This form of BSC amounts to a framework capable of driving management innovation and renewing the ways in which companies conceive their strategy and perform their operations. Since BSC draws integrally on user participation, it can be expected that users' satisfaction with BSC systems is an important factor in systems' success or failure. However, previous studies of the BSC system have not yet considered it as a theoretical model, specifically examining BSC system and task characteristics. To date, only a few studies have put forward plans for the implementation and use of BSC systems, and these studies have the common limitation of failing to consider the circumstances or theoretical structure of the companies for which a BSC system is being proposed. This paper then begins to fill some of this gap by characterizing the BSC system from the perspective of contingency theories. Contingency theories can be particularly useful in the Korean context in exploring how different companies use the BSC system in ways determined by their unique environmental characteristics, which may also determine the performance factors behind the application of a company's particular BSC system. In order to provide concrete suggestions for implanting and using the BSC system from a contingency theory perspective, this study sets out to determine the relationships between the contingency variables affecting BSC system performance and BSC system property variables(in given cases) through an empirical analysis. The study takes into account the perspective from which contingency theory is to be applied in individual cases, sets contingency and BSC property variables with reference to the BSC system user's environment and BSC system's character, and frames initial hypotheses concerning corporate structure and environmental variables and BSC system performance variables with reference to previous studies. A survey was then conducted on users in Korean companies that have implemented the BSC system in order to verify the research model and understand results.

• Journal of Intelligence and Information Systems
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• v.15 no.1
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• pp.51-64
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• 2009

A location tracking sensor such as GPS, INS, Radar, and optical equipments is used in tracking Maneuvering Targets with a multi-sensor, and such systems are used to track, detect, and control UAV, guided missile, and spaceship. Until now, Most of the studies related to tracking Maneuvering Targets are on fusing multiple Radars, or adding a supplementary sensor to INS and GPS. However, A study is required to change the degree of application in fusions since the system property and error property are different from sensors. In this paper, we perform the error analysis of the sensor properties by adding a ground radar to GPS and INS for improving the tracking performance by multi-sensor fusion, and suggest the tracking algorithm that improves the precision and stability by changing the sensor probability of each sensor according to the error. For evaluation, we extract the altitude values in a simulation for the trajectory of UAV and apply the suggested algorithm to carry out the performance analysis. In this study, we change the weight of the evaluated values according to the degree of error between the navigation information of each sensor to improve the precision of navigation information, and made it possible to have a strong tracking which is not affected by external purposed environmental change and disturbance.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.3
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• pp.1059-1065
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• 2010

Very-early strength latex-modified concrete (VES-LMC) was developed for the purpose of fast-track overlay of a concrete bridge deck under heavy traffic, concentrated on the workability, durability, and strength gain so that it can be opened to the traffic only three hours after its placement. The mixture of VES-LMC might accompany very high heat of hydration at early-age because of its inherent rapid hardening property and could have susceptibility to autogenous shrinkage because of its relatively low water-cement ratio. This study evaluated the effect of the latex-cement ratio(L/C) both of the constant and variable slumps on the autogenous shrinkage of VES-LMC by carrying out simple temperature rise test and early-age shrinkage experiment. Test results are as follows: The latex contributes on the enhancement of the concrete durability but has little effect on its hydration and the accompanied heat of hydration in VES-LMC. Autogenous shrinkage increased with the increase in latex-cement ratio at variable slumps and its pattern followed regularly a logarithmic increase. However, the influence of water-cement ratio and latex-cement ratios for the test specimens at constant slump on early-age autogenous shrinkage property was found to be minor due to the simultaneous effect of the two experimental variables.

• Science of Emotion and Sensibility
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• v.20 no.4
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• pp.55-64
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• 2017

This study was performed to help the denim fabric planning which reflects the sensibility preference of university students. Objective characteristics, like color properties and mechanical properties, in 8 denim fabrics (5 cotton 100% fabrics and 3 cotton/polyurethane blended fabrics) were evaluated. And the color preference, subjective sensation and tactile preference of denim fabrics were investigated among the university students. The effect of color preference and tactile preference of denim fabrics on the purchase preference of denim slacks was also examined. Color preference of denim fabrics showed a significant difference according to the kind of denim fabrics. University students preferred purple blue denim fabrics that was measured low $-b^*$ value and low $C^*$ value among the color properties of denim fabrics. Among the mechanical properties of denim fabrics, surface property like MMD, MIU and SMD as well as shear property like 2HG5 were important elements affecting subjective sensation. While, tactile preferences showed a significant difference according to the fabrics. The tactile preferences of cotton/polyurethane blended denim fabrics was highly preferred, and that of heavy 100% cotton denim fabric was lowly preferred. And the subjective sensation affecting tactile preferences were in order of smoothness, softness, lightness. It is concluded that the color preference and tactile preference influenced upon the purchase preference of denim slacks, and color preference had a bigger effect upon the purchase preference.

• Polymer(Korea)
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• v.35 no.3
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• pp.238-243
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• 2011

Organic/inorganic hybrid materials have a lot of interest in various areas due to their fascinating properties. To control the location and dispersion of inorganic nanoparticles within polymer matrix. thiol-terminated polymeric ligands have been widely used to tune the surface property of nanoparticles. However, the specific binding between the thiol functional group and metal is unstable with increasing temperature. To archive the thermally-stable Au nanoparticles, we previously synthesized various UV-crosslinkable polymeric ligands, which have different compositions of polar, UV-crosslinkable azide unit comparing to non-polar 스티렌 units. After crosslinking the Au nanoparticles, it was found that the nanoparticles had superb stability at high temperature (above $180^{\circ}C$). In this work, we used thermally-stable Au nanoparticles to control the location within the polymer matrix. By changing the amount of polar azide units in the polymeric ligands, we could precisely control the location of nanoparticles from one domain to the interface of block copolymer templates.

• Korean Journal of Food Science and Technology
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• v.51 no.2
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• pp.109-113
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• 2019

The soft rice varieties, Hangaru and Singil, were developed via mutation breeding using N-methyl-N-nitrosourea treatment to obtain dry-milled rice flours. The physicochemical, morphological, and pasting properties of these starches were compared with those of Seolgaeng and Chuchung starches. Singil starch was found to exhibit the highest amylose content and initial pasting temperature, whereas Hangaru starch exhibited the highest water binding capacity and swelling power. Hangaru starch's granule size at $d_{50}$ was the largest among the four different starch types. Some Seolgaeng, Hangaru, and Singil granules were observed to have a round-faced polygon shape. Furthermore, the crystallinity of all four starch types was type A. The peak, trough, and final viscosities of the soft rice starches were also lower than those of normal starches. Notably, Hangaru starch showed the highest breakdown viscosity, but the lowest total setback viscosity among the four starches. From these results, the starch characteristics of the soft rice flours were discovered to be different based on the rice variety.

• Journal of the Korean Electrochemical Society
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• v.8 no.2
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• pp.94-98
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• 2005

Coptp films with the additive elements (X=Fe, Mn) of varying concentrations were prepared by in-situ electrodeposition, to tailor their magnetic properties. Alloys of CoPtP-X (X=Fe, Mn) were synthesized by changing the solution concentrations of Fe and Mn for electrodeposition. In the electrodeposited CoFePtP alloys, preferred orientation of the electrodeposited films changed from hexagonal (001) to (100) direction with increasing iron contents as revealed by X-ray diffraction, and these films exhibited various magnetic properties ranging from a typical hard magnetic to a soft magnetic property in accordance with microstructural variations. In the case of Mn addition, excellent hard magnetic property was observed at a specific Mn concentration of 0.0126 M in the electrolyte, with the coercivity of 4630 Oe and squareness of 0.856 and this was attributed to the fact that magnetization easy-axis (hexagonal c-axis) coincides with the preferred growth orientation of the film confirmed by transmission electron microscopy.