• Korean Journal of Mineralogy and Petrology
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• v.33 no.3
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• pp.259-272
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• 2020

The seismic properties in the crust are affected by the lattice preferred orientation(LPO) of major minerals in the crust. Therefore, in order to understand the internal structure of the crust using seismic data, information on the LPO of the major constituent minerals and the seismic properties of major rocks in a specific region are needed. However, there is little research on the LPOs of minerals in the crust in Korea. In this study, we collected amphibolites from two outcrops in Wigokri, Gapyeong, located in the nothern portion of Gyeonggi Massif, and we measured the LPOs of major minerals of amphibolite, especially amphibole and plagioclase through EBSD analysis, and calculated seismic properties of amphibolite. Two types of LPOs of amphibole, which are defined as type I and type IV, were observed in the two outcrops of Gapyeong amphibolites, respectively. In the case of amphibolites with the type I LPO of amphibole, large seismic anisotropy of both P- and S-wave was observed, while in the amphibolites with the type IV LPO of amphibole, small seismic anisotropy was observed. This is consistent with previous experimental results. The polarization direction of the fast S-wave was aligned subparallel to the lineation regardless of the LPO types of amphibole. The seismic anisotropy observed in Gapyeong is expected to be helpful to interpret the structure and seismic data within the crust in Gyeonggi Massif.

• Journal of the Korean Chemical Society
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• v.55 no.3
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• pp.502-508
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• 2011

Synthesis of $Nd_{2x}Cd_{2-3x}SiO_4$ ($0.01{\leq}x{\leq}0.21$) [S1-S3: x=0.01, 0.11 and 0.21] solid solutions were prepared by solgel method. Powder x-ray diffraction (XRD) results show monoclinic unit cell with space group P21/m. The average crystallite sizes are found to be 20 to 45 nm. The Scanning Electron Microcopy (SEM) images show morphology of the sample is in globular nature. The energy dispersive analysis of x-rays (EDX) and X-ray mapping results confirmed that all the constituent elements of the composites were present and that were distributed in uniformly. The optical absorption band at ~750 nm was due to $^4I_{9/2}{\rightarrow}^4F_{7/2}+^4S_{3/2}$ transition optically active $Nd^{3+}$ ions. Electron Paramagnetic Resonance (EPR) lineshapes of S1-S3 at 10, 40, 77 and 300 K show a broad unresolved isotropic lineshapes were observed due to rapid spin lattice relaxation of $Nd^{3+}$.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.10
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• pp.40-48
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• 2008

Security of self organized mobile ad hoc networks is an important issue because administration information in the networks is managed by the constituent nodes. Especially authentication mechanism is necessary for trust setup between newly joining nodes and the network. The authentication models and protocols which are based on the wireline infrastructure could not be practical for mobile ad hoc network. Although public key algorithm-based method is widely used for authentication, it is not easy to be applied to mobile ad hoc networks because they do not have infrastructure such as centralized CA which is needed for certificate verification. In this paper, we consider the public key based random CA group method proposed in [1] to provide efficient authentication scheme to mobile ad hoc networks and analyze the performance of the method, which is then compared to the home CA method. From the analysis results, we see that the random CA method where the function of CA is distributed to some mobile nodes and the authentication information is propagated to randomly chosen CAs shows higher reliability and lower cost than home CA method.

• Korean journal of applied entomology
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• v.44 no.1 s.138
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• pp.37-41
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• 2005

Essential oil of five plants were screened for fumigation toxicity against Blattella germanica male adults. Among them, coriander oil showed $100\%$ fumigation toxicity against B. germanica male adults at 20 and $10{\mu}{\ell}/{\ell}$ (air) dose, respectively. Through the constituent analysis using GC and GC/MS, we confirmed that main constituents of coriander oil were ${\alpha}$-pinene ($6.1\%$), camphene ($1.1\%$), ${\beta}$-pinene ($0.5\%$), ${\beta}$-myrcene ($0.8\%$), limonene ($2.5\%$), ${\gamma}$-terpinene ($4.5\%$), ${\rho}$-cymene ($1.8\%$), ${\alpha}$-terpinolene ($0.5\%$), camphor ($4.9\%$), linalool ($70.5\%$), ${\alpha}$-tepineol ($0.7\%$), geranyl acetate ($2.8\%$) and geraniol ($1.4\%$). Among them, ${\gamma}$-terpinene and geranyl acetate showed $100\%$ fumigation toxicity at $10{\mu}{\ell}/{\ell}$ (air) dose, respectively. It can be concluded that coriander oil is potential control agents against B. germanica.

• Journal of Dental Rehabilitation and Applied Science
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• v.22 no.4
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• pp.349-365
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• 2006

State of problem : A number of investigation about increase of surface area via various surface treatments and modification of surface constituent have been carried out. Purpose : The surface characteristics and stability of implants treated with anodic oxidation, fluoride ion incorporation, and groups treated with both methods were evaluated. Material and method : Specimens were divided into six groups, group 1 was the control group with machined surface implants, groups 2 and 3 were anodic oxidized implants (group 2 was treated with 1M $H_2SO_4$ and 185V, group 3 was treated with 0.25M $H_2SO_4$ and $H_3PO_4$ and 300V). Groups 4, 5 and 6 were treated with fluoride. Group 4 was machined implants treated with 0.1% HF, and groups 5 and 6 were groups 2 and 3 treated with 10% NaF respectively. Using variable methods, implant surface characteristics were observed, and the implant stability was evaluated on rabbit tibia at 0, 4, 8 and 12 weeks. Result : 1. In comparison of the surface characteristics of anodic oxidized groups, group 2 displayed delicate and uniform oxidation layer with small pore size containing Ti, C, O and showed mainly rutile, but group 3 displayed large pore size and irregular oxidation layer with many crators. 2. In comparison of the surface characteristics of fluoride treated groups 4, 5, 6 and non-fluoride treated groups 1, 2, 3, the configurations were similar but the fluoride treated groups displayed rougher surfaces and composition analysis revealed fluoride in groups 4, 5, 6. 3. The fluoride incorporated anodic oxidized groups showed the highest resonance frequency values and removal torque values, and the values decreased in the order of anodic oxidized groups, fluoride treated group, control group. 4. According to implant stability tests, group 2 and 3 showed significantly higher values than the control group (P<.05). The fluoride treated groups showed relatively higher values than the non fluoride treated groups and there were significant difference between group 4 and group 1 (P<.05). Conclusion : From the results above, it can be considered that the anodic oxidation method is an effective method to increase initial bone stability and osseointegration and fluoride containing implant surfaces enhance new bone formation. Implants containing both of these methods should increase osseointegration, and reduce the healing period.

• Science of Emotion and Sensibility
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• v.9 no.spc3
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• pp.187-196
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• 2006

This study has showed verified results on 'Survey into Observer Preference for Table Decoration for Eating and Drinking'. It is a preliminary study to look into interrelation of preference to color tables, image adjectives, aesthetic value, by giving color changes in a certain regularity to each influential factor in functional table decoration. The result has demonstrated that, as for color image and preference,'observers prefers mid/low dark-toned brown which gives a feeling of 'high-quality, and like to eat', and orange tone with a fooling of 'warm and colorful'. In evaluating interrelation between preference and aesthetic value, the study has revealed that ordinary people take the influential factor of 'unity and Gestalt' seriously, while non-professionals preferred 'uniqueness'. Stimulant No. 7 is one of constituent factors of functional table decoration, eliciting significance of images on colors ant aesthetic value. This study also has practical problems about insufficiency or inadequateness in producing mood suitable to T P O, according to depending upon color changes in picking up stimulants, or other problems in selecting stimulants, according to time, seasons and generational parameter in which the inquiry is conducted, but it will serve as a stepping stone for developing new design using both qualitative and quantitative data in 려nctional table decoration.

• Journal of Distribution Research
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• v.11 no.2
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• pp.29-57
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• 2006

While a number of studies have recognized the importance of environment of channel systems and consequences of changed environment, only limited studies have dealt with this issue theoretically and practically. The purpose of this study is to empirically validate whether one dimension of environment, called dynamism, has an influence on the relationship characteristics such as transaction specific investment opportunism and conflict or not: further, it is designed to delve into whether these relationship characteristics have any influence on one crucial relationship quality, 'trust' and its two constituent dimensions - credibility and benevolence. In order to provide empirical validation, a survey was conducted to 163 sales office managers at a major newspaper publisher in Korea. An analysis of the data retrieved from this survey indicated that while environmental dynamism has a positive influence on the publisher's opportunism and conflict perceived by the sales office managers, it did not show a direct influence on the transaction specific investment made by the publisher. Furthermore, while publisher's transaction specific investment had a positive influence on the credibility and the benevolence respectively, publisher's opportunism and level of sales office conflict had a negative influence on the credibility and the benevolence respectively. Currently, a publisher is facing an unprecedentedly dynamic environment. This study should provide ample implications for the publisher in establishing trust, which is a crucial condition in developing and maintaining a long-term successful relationship with its sales offices.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.2
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• pp.166-176
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• 2009

Eighteen Korean chestnut cultivars were collected from various places and the proximate compositions, dietary fiber, amino acid and free sugar contents in three parts (whole kernel, white kernel, yellow kernel) of eighteen Korean chestnut cultivars were analyzed. The white kernel of Chukfa and the yellow kernel of Ipyung contained the highest amount of moisture and crude protein, respectively. Carbohydrate content of whole kernel showed a range of $30.8{\sim}52.0%$ and crude ash content of whole kernel showed a range of $0.9{\sim}1.8%$. The amount of crude lipid was the highest in Byunggo. The amount of dietary fiber in Kwangeun, Daebo, Parkmi 1 ho, Yooma and Pyeonggi were higher than that of other Korean chestnut cultivars. Seventeen amino acids were detected. Major amino acids of the various chestnuts were aspartic acid and leucine. The amount of amino acids was higher in Ichui, Ipyung and Pyeonggi but was lower in Dantaek and Sandae than that of other samples. The major free sugar in the chestnuts was glucose. The free sugar amount of yellow kernels was higher than the white kernels.

• Composites Research
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• v.12 no.3
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• pp.75-83
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• 1999

The thermal properties of carbon/phenolic and silica/phenolic ablative composites were investigated by measuring the heat capacity, thermal diffusivity and thermal conductivity. The heat capacities of carbon/ phenolic and silica/phenolic composites were calculated from differential scanning calorimeter curve. The thermal diffusivities of carbon/phenolic and silica/phenolic composites were measured by the laser flash method with varying laminated direction, i.e., with laminar direction and across laminar direction. The thermal diffusivities decreased with increasing temperature. The thermal conductivities of carbon/phenolic and silica/phenolic composites were calculated using the heat capacity, density and thermal diffusivity. The thermal conductivities increased with increasing temperature. The thermal conductivity of with laminar direction is two times higher than that of across-laminar direction in carbon/phenolic composite due to the directionality of thermal conductivity of carbon fiber. The thermal conductivities of two dimensional fiber reinforced composites were analyzed using the conductivities of constituents and volume fraction of each constituent. The thermal conductivities of carbon fiber and silica fiber were calculated from thermal conductivities of carbon/phenolic and silica/phenolic composites. The thermal conductivities of carbon/phenolic and silica/phenolic composites at RT were predicted from thermal conductivities of fiber and resin with varying the volume fraction of fiber.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.6
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• pp.682-692
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• 2008

Fine particles ($PM_{2.5}$) were collected and analyzed from November 2005 through August 2007 in Chuncheon, Korea to investigate the characteristics of $PM_{2.5}$ and its ionic constituents. The average $PM_{2.5}$ concentration during the study period was $39{\mu}g/m^3$, which is almost two times higher than the annual US NAAQS $PM_{2.5}$ standard of $15{\mu}g/m^3$. $PM_{2.5}$ concentrations were higher in spring and winter than in summer and fall. During spring, Asian Dust events dramatically enhanced $PM_{2.5}$ concentrations, and long-range transport of $PM_{2.5}$ emitted in industrial area of China often occurred during winter based on trajectory analysis. Contribution of $PM_{2.5}$ to $PM_{10}$ concentrations ranged from $72{\mu}g/m^3$ during Asian Dust events to $457{\mu}g/m^3$, indicating that a large portion of $PM_{2.5{\sim}10}$ was transported from China during Asian Dust events. Among the major ionic constituents ${SO_4}^{2-}$ showed the highest concentration, followed by ${NH_4}^+$, ${NO_3}^-$ and ${NO_2}^-$. Chuncheon appeared to be ${NH_4}^+$ rich environment, indicating that $(NH_4)_{2}SO_4$ and ${NH_4}{NO_3}$ were the predominant forms of ${NO_3}^-$ and ${SO_4}^2$ in $PM_{2.5}$. Haze has frequently occurred in Chuncheon since So-Yang dam was constructed in 1973. Haze events were observed on 23 days during sampling period, and the average $PM_{2.5}$ concentration was approximately 1.6 times higher during haze events than during non-haze events. This result suggests that haze enhances the secondary aerosol formation because the aerosol spontaneously absorbs water to form a saturated salt solution, deriving a significant increase in the mass of the particle.