• The Journal of Natural Sciences
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• v.8 no.1
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• pp.61-69
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• 1995

It is hard to synthesize pure $BaTiO_3$ from $BaCO_3$ and $TiO_2$ in solid reaction for the activity of BaO and secondary phase. For this reason, the wet chemical techniques have been studied. Starting material which was used in these methods were expensive and the properties of powder which was synthesized in same defined. So, some process have been studying again to improve soild reaction method. This study which was one of those was to defin the forming mechanism of $Ba_2TiO_4$ and to control some condition of $Ba_2TiO_4$. The synthesis temperature of $BaTiO_3$ in solid reaction was near $1120^{\circ}C$. The quantity and forming temperature of $Ba_2TiO_4$ could be controlled by atmosphere heat treatment. $Ba_2TiO_4$ was related to expansion in Ba-rich region of $BaTiO_3$. $BaTiO_2O_5$ and $BaTiO_3O_7$ was reason to expand in Ti-rich region. The dielectrics of $CeAIO_3$ which was synthesized and sintered in reduction atmosphere and $BaTiO_3$ system were affected by $CeO_2$ which was formed for the decomposition of $CeAIO_3$ heat treatment in air.

• Korean Journal of Optics and Photonics
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• v.18 no.6
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• pp.375-382
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• 2007

The Shack-Hartmann wavefront sensor is composed of a lenslet array generating the spot images from which local slope is calculated and overall wavefront is measured. Generally the principle of wavefront reconstruction is that the spot centroid of each lenslet array is calculated from pixel intensity values in its subaperture, and then overall wavefront is reconstructed by the local slope of the wavefront obtained by deviations from reference positions. Hence the spot image of each lenslet array has to remain in its subaperture for exact measurement of the wavefront. However the spot of each lenslet array deviates from its subaperture area when a wavefront with large local slopes enters the Shack-Hartmann sensor. In this research, we propose a spot image searching method that finds the area of each measured spot image flexibly and determines the centroid of each spot in its area Also the algorithms that match these centroids to their reference points unequivocally, even if some of them are situated off the allocated subaperture, are proposed. Finally we verify the proposed algorithm with the test of a defocus measurement through experimental setup for the Shack-Hartmann wavefront sensor. It has been shown that the proposed algorithm can expand the dynamic range without additional devices.

• Journal of dental hygiene science
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• v.15 no.6
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• pp.836-844
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• 2015

The objective of this research is to analyze geographical distribution of Korean dental hygienists to provide the geographical basis of supply-side policy for dental hygienists from the perspective of dental geography by using Geographic Information System (GIS) in which the choropleth map has been regarded as the most popular method. The present report is highly meaningful for the policy of dental hygienist on the supply side of dental care market. The data used in the article derive from the statistics-associated portal site provided by Korean government. It includes the statistics on general population, the regional numbers of dental hygiene students, county-based numbers of registered dental hygienists, dentists, and dental clinics and hospitals. Several maps are created by investigating these statistical data with GIS. This study is focused on the comparative analysis between entrants to the department of dental hygiene, registered acting dental hygienists and dentists in terms of county-based distribution per its population. The main result demonstrates that whereas about half of dental hygienists and dentists are respectively concentrated in Seoul and Gyung-gi, just one-fifth of entrants to the department of dental hygiene in the Seoul-metropolitan area. From the perspective of the supply-side policy of dental hygienists, the research argues that the creation or expansion of the department of dental hygiene does not directly meet social need for dental care services.

• Journal of Digital Convergence
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• v.10 no.11
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• pp.93-102
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• 2012

The purpose of this research is to create a preferable corporate culture under the SmartWork environment. There is growing interests in SmartWork, which can satisfy the compatible conditions of government's carbon emission restriction policy, corporate efficient expense reduction, productivity maximization, and each individual's work and a family. Due to the interests and the rapid development of IT technology, a realistic condition for SmartWork is established but the promotion without a sufficient preparation, such as legal examination and relevant systems, created much confusion and very few companies are introducing it. This paper discusses that a social agreement should be reached through adjustments among parties interested, such as government, companies, and employees, studies the WIN-WIN plan that individuals and organization can grow together, and proposes a new corporate culture under the SmartWork environment. SmartWork has more than the simple meaning of 'remote working'. SmartWork, a method of smart working, means a transition to a new paradigm that minimizes moving for work and work & human move together, and a change from a work-oriented culture to a human-oriented culture. This paper summarized the role of government and companies for the successful introduction of SmartWork, and proposed that a government level 'SmartWork Activation Executive Committee (tentative name)' with a strong promotional power would create a new culture of SmartWork and form a civilian consultative body to support SmartWork corporate culture creation & expansion in the private corporate area, in a tuning with Ministry of Public Administration & Security, Ministry of Labor, Ministry of Gender, and Communications Commission.

• Nuclear Engineering and Technology
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• v.27 no.3
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• pp.393-402
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• 1995

The structural analysis of the reactor coolant system mainly consist of too fields. The one is the static analysis considering the impact of pressure and temperature built up during normal operation. The other is the dynamic analysis to estimate the impact of postulated events such as the seismic loads or postulated branch line pipe breaks event. Since the most important goal of the RCS structural analysis is to prove the safety of the RCS during normal operation or postulated events, a widely proven theory having enough conservatism is adopted. The load occurring on the RCS during normal operation is considered as the basic design loading condition throughout whole plant life time. The most typical characteristic of the RCS during normal operation is the thermal expansion of the RCS caused by reactor coolant with high temperature and pressure. Therefore, the exact estimation on the thermal movement of the RCS is needed to get more clear understanding on the thermal movement behavior of the RCS. In this study, the general structural analysis concept and modeling method to evaluate the thermal movement of the RCS under the normal plant operation condition are presented. To discuss the validation of the suggested analysis, analysis results are compared with the measured data which ore referred from the standardized 1000 MWe PWR plant under construction.

• Journal of Microbiology
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• v.45 no.5
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• pp.460-465
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• 2007

This study was carried out in order to investigate the potential of using plant oils derived from Leptospermum petersonii Bailey and Syzygium aromaticum L. Merr. Et Perry as natural antifungal agents. The antifungal effects of essential oils at concentrations of 0.05, 0.1, 0.15, and 0.2 mg/ml on the dermatophytes Microsporum canis (KCTC 6591), Trichophyton mentagrophytes (KCTC 6077), Trichophyton rubrum (KCCM 60443), Epidermophyton floccosum (KCCM 11667), and Microsporum gypseum were evaluated using the agar diffusion method. The major constituents of the active fraction against the dermatophytes were identified by gas chromatography-mass spectrometry and high-performance liquid chromatography analysis. The antifungal activities of S. aromaticum oil (clove oil) against the dermatophytes tested were highest at a concentration of 0.2mg/ml, with an effectiveness of more than 60%. Hyphal growth was completely inhibited in T. mentagrophytes, T. rubrum, and M. gypseum by treatment with clove oil at a concentration of 0.2 mg/ml. Eugenol was the most effective antifungal constituent of clove oil against the dermatophytes T. mentagrophytes and M. canis. Morphological changes in the hyphae of T. mentagrophytes, such as damage to the cell wall and cell membrane and the expansion of the endoplasmic reticulum, after treatment with 0.11 mg/ml eugenol were observed by transmission electron microscopy (TEM). At a concentration of 0.2 mg/ml, L. petersonii oil (LPO) was more than 90% effective against all of the dermatophytes tested, with the exception of T. rubrum. Geranial was determined to be the most active antifungal constituent of L. petersonii oil. Taken together, the results of this study demonstrate that clove and tea tree oils exhibited significant antifungal activities against the dermatophytes tested in this study.

• Journal of Wetlands Research
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• v.22 no.4
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• pp.245-256
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• 2020

The purpose of this study is to evaluate the technological competitiveness of the environmental industry with developed countries in order to establish an international market expansion strategy of the Korean environmental industry and technology. In order to evaluate the competitiveness of the environmental industry and technology, core technologies were classified by the environmental industry sectors based on the classification system of the domestic and international environmental industry and technology. After developing the evaluation index data, the Delphi analysis, journal and patent analysis, as well as the export and import analysis were carried out and the standardization analysis was performed on the index data. Moreover, the weights of each evaluation index were calculated using the AHP(Analytic Hierarchy Process) method and the evaluation results of competitiveness of the environmental industry and technology in Korea, the United States, the United Kingdom, Germany, and France were derived. As a result of the evaluation, the United States was rated with the highest technological competitiveness in all the environmental industry sectors, while Korea got the lowest technological competitiveness rating compared to the 4 developed countries. In particular, Korea got the lowest level of technological competitiveness in the sector of multi-media environmental management and development for a sustainable social system. Therefore, in order for the Korean environmental industry and technology to enter the global advanced market, it is necessary to strengthen the competitiveness through the development of the fourth environmental industry based on IoT(Internet of Things), cloud, big data, mobile, and AI(Artificial Intelligence), which are currently the country's domestic strengths.

• Journal of Cadastre & Land InformatiX
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• v.45 no.1
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• pp.31-43
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• 2015

In the past, the main function of land use categorization was merely used for basic data for taxation purpose, but recently land use categorization is used as important reference data in various ways, including administrative affairs, national land plan, land development, city maintenance as well as private transactions of land, in addition to the provision for assessment data. In the future, it can be expected to broaden its own functions. For expansion of the function of land use, we need to reconsider categories of land use from a perspective of individual laws and regulations actually regulating land use from a perspective of demand. In order to resolve any discrepancy between actual land use and land use on official books, the ultimate method of resolution is to study the current state of actual use of land and reflect them on official books, but it is also necessary to prevent any confusion of national people by unifying various categories of land adopted by the regulatory acts related to land. In addition, if the same administrative regulations are applied to different land use under the current laws, it is necessary to include them in the land of the same category. This study proposes to establish a new category for securing systematic consistency of the current categories of land use under the integrated cadastral act with other land laws and regulations.

• Cartoon and Animation Studies
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• s.46
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• pp.1-22
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• 2017

The practical learning requires the new paradigm in its content of education and environment along with the rapid development of information communication technology and the expansion of digital content industry. Especially, the animation education, core area of digital content industry, has attempted to improve the content and method of education by focusing on creativity, convergence and practical education. However, education environment in the previous form of computer laboratory has not been reflected the characteristics of animation education. In the light of this, this research would suggests the effective education environment implemented animation job competency and the characteristics of animation production. Firstly, the problem of previous educational environment will be explored through looking at computer rooms of domestic Universities. The characteristics of animation production consisted of Pre-production, Main-production, Post-production and elements of animation job competency will be reviewed by focusing on three phases of production, Pre-production, Main-production and Post-production, and six particular jobs, concept art, modeling & texturing, animating, lighting, VFX and compositing. Secondly, 6 types of space adapted from space syntax, possibly explored the embedded meaning of the structure of space and environment, will be reviewed by focusing on integration, separation and interaction. Thirdly, based on the characteristics of animation production, the element of animation job competency, 6 types of space, analytical tools about animation project education will be deducted, and the case study regarding animation studio, Walt Disney studio, will be processed by focusing on its production environment and spatial composition by focusing on Pre-production, Main-production, Post-production. Fifthly, the effective spatial composition for animation project education will be explored based on the interpretation of literature reviews and case study. In regard to this, the research addresses the spatial composition reflected the characteristics of practical learning and job competency in animation education, which differs from the previous form of standardized education spaces.

• Restorative Dentistry and Endodontics
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• v.25 no.3
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• pp.359-370
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• 2000

The purpose of this investigation was to observe the viscoelastic properties of five commercial flowable(Aeliteflo, Flow it, Revolution, Tetric flow, Compoglass flow), three conventional hybrid(Z-100, Z-250, P-60) and two condensable(Synergy compact, SureFil) resin composites. A dynamic oscillatory shear test was done to evaluate the storage shear modulus (G'), loss shear modulus(G"), loss tangent(tan ${\delta}$) and complex viscosity(${\eta}^*$) of the resin composites as a function of frequency - dynamic frequency sweep test from 0.01 to 100 rad/s at $25^{\circ}C$ - by using Advanced Rheometric Expansion System(ARES). To investigate the effect on the viscosity of resin composites of filler volume fraction, the filler weight % and volume % were measured by means of Archimedes' principle using a pyknometer. The results were as follows 1. The complex viscosity ${\eta}^*$ of flowable resins was lower than that of hybrid resins and significant differences were observed between brands. The complex viscosity ${\eta}^*$ of condensable resins was higher than that of hybrid resins. The order of complex viscosity ${\eta}^*$ at ${\omega}$=10 rad/s was as follows, Surefil, Synergy compact, P-60, Z-250, Z-100, Aeliteflo, Tetric flow, Compoglass flow, Flow it, Revolution. The relative complex viscosity of flowable resins compared to Z-100 was 0.04~0.56 but Surefil was 30.4 times higher than that of Z-100. 2. The storage shear modulus G' and the loss shear modulus G" of flowable resins were lower than those of hybrid resins but those of condensable resins were higher. The patterns of the change of loss tangent, tan ${\delta}$, of resin composites with increasing frequency were significantly different between brands. The phase angles, ${\delta}$, ranged from $30.2{\sim}78.1^{\circ}$ at ${\omega}$=10 rad/s. 3. All composite resins represent pseudoplastic nature with increasing shear rate. 4. The complex shear modulus $G^*$ and the phase angle ${\delta}$ was represented by the frequency domain phasor form, $G^*({\omega})=G^*e^{i{\delta}}=G^*{\angle}{\delta}$. The locus of frequency domain phasor plots in a complex plane was a valuable method that represent the viscoelastic properties of composite resins. 5. There was no direct linear correlationship but a weak positive relation was observed between filler volume % or weight % and the viscosity of the resin composites.