• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.222-222
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• 2012

Metal oxide gas sensors based on semiconductor type have attracted a great deal of attention due to their low cost, flexible production and simple usability. However, most works have been focused on n-type oxides, while the characteristics of p-type oxide gas sensors have been barely studied. An investigation on p-type oxides is very important in that the use of them makes possible the novel sensors such as p-n diode and tandem devices. Monoclinic cupric oxide (CuO) is p-type semiconductor with narrow band gap (~1.2 eV). This is composed of abundant, nontoxic elements on earth, and thus low-cost, environment-friendly devices can be realized. However, gas sensing properties of neat CuO were rarely explored and the mechanism still remains unclear. In this work, the neat CuO layers with highly ordered mesoporous structures were prepared by a template-free, one-pot solution-based method using novel ink solutions, formulated with copper formate tetrahydrate, hexylamine and ethyl cellulose. The shear viscosity of the formulated solutions was 5.79 Pa s at a shear rate of 1 s-1. The solutions were coated on SiO2/Si substrates by spin-coating (ink) and calcined for 1 h at the temperature of $200{\sim}600^{\circ}C$ in air. The surface and cross-sectional morphologies of the formed CuO layers were observed by a focused ion beam scanning electron microscopy (FIB-SEM) and porosity was determined by image analysis using simple computer-programming. XRD analysis showed phase evolutions of the layers, depending on the calcination temperature, and thermal decompositions of the neat precursor and the formulated ink were investigated by TGA and DSC. As a result, the formation of the porous structures was attributed to the vaporization of ethyl cellulose contained in the solutions. Mesoporous CuO, formed with the ink solution, consisted of grains and pores with nano-meter size. All of them were strongly dependent on calcination temperature. Sensing properties toward H2 and C2H5OH gases were examined as a function of operating temperature. High and fast responses toward H2 and C2H5OH gases were discussed in terms of crystallinity, nonstoichiometry and morphological factors such as porosity, grain size and surface-to-volume ratio. To our knowledge, the responses toward H2 and C2H5OH gases of these CuO gas sensors are comparable to previously reported values.

• Journal of the Korean Association of Geographic Information Studies
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• v.3 no.3
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• pp.69-76
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• 2000

This study deals with development GIS application using web-based CAD, this application serves to user, designer, manager that more convenient and various functions. Development to this application, collect attribute data from fieldwork and geographic data from cadastral map and aerial survey map and then development to user interface using HTML, JavaScript, ASP, Whip ActiveX control. This application's characters are as follows ; First, system designer designed that anyone who have basic knowledge about web and CAD can develop this application. A system structure simplification by 2-Tier. Geographic information use DWF(drawing web format) file and attribute information use DBMS in consideration of extension. Second, system manager can service independently GIS in Web need not high priced GIS engine, so more economical. Third, internet user get service GIS information and function that search of information, zoom in/out, pan, print etc., if you need more functions, add function without difficultly. Developed application as above, not only save volume but fast of speed as use vector data exclude character and image data. Also, this application can used by means of commercial and travel information service but also various GIS service of public institution and private in web.

• Journal of the Korean Association of Geographic Information Studies
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• v.9 no.1
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• pp.20-33
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• 2006

Changing of industry structure and development of traffic and telecommunications requires a change of the knowledge about the space where the human beings reside. Step by step the world is being divided into specified utility blocks. Today there is a limit that only one local government can compete with another region in the world. This study provides decision support tools with the use of GIS on the regional level for regions competition. GIS establishes regions and analyzes their geographic environment data, which will help in local-government problem solving and provide framework data for similar regions to become the community. The wide-area GIS application can present an objective and rational basis for regulation of inefficient investments and excessive competition between adjacent regions. The study area is Gangwon-do. Considering specific features of Gangwon-do which preserved high-quality environment resources, river basins were taken as a basis among natural regional elements. The main object of analysis conducted were the facts relevant to environmental regulation. The Gangwon-do consists of three regions in this study: Yongdong region, North-Hangang region and South-Hangang region. The analysis of each region regulation cases showed the following: in Youngdong region the forests regulation rate is high, in North-Hangang region the military installations protection sector's rate as well as regulation rate for water resources protection is relatively high, in South-Hangang region the forest and water resources regulation rate is high. The percentage of forests and water regulation rate appeared to be rather high in Gangwon-do, which means that the value of forest and water resources there is very high.

• Journal of Internet Computing and Services
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• v.15 no.3
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• pp.63-69
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• 2014

For the safety messages in IEEE 802.11p vehicles network environment(WAVE), strict periodic beacon broadcasting requires status advertisement to assist the driver for safety. WAVE standards apply multiple radios and multiple channels to provide open public road safety services and improve the comfort and efficiency of driving. Although WAVE standards have been proposed multi-channel multi-radio, the standards neither consider the WAVE multi-radio environment nor its effect on the beacon broadcasting. Most of beacon broadcasting is designed to be delivered on only one physical device and one control channel by the WAVE standard. also conflict-free channel assignment of the fewest channels to a given set of radio nodes without causing collision is NP-hard, even with the knowledge of the network topology and all nodes have the same transmission radio. Based on the latest standard IEEE 802.11p and IEEE 1609.4, this paper proposes an interference aware-based channel assignment algorithm with Nash bargaining solution that minimizes interference and increases throughput with wireless mesh network, which is deigned for multi-radio multi-cahnnel structure of WAVE. The proposed algorithm is validated against numerical simulation results and results show that our proposed algorithm is improvements on 8 channels with 3 radios compared to Tabu and random channel allocation algorithm.

• Journal of Educational Research in Mathematics
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• v.26 no.2
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• pp.247-267
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• 2016

It has been pointed out that the mathematics textbooks according to 2009 revised national curriculum cause difficulty not by mathematical knowledge but concomitantly by words and sentences for the first graders who just started learning Korean alphabets. This study focused on the suitability of words and sentences in mathematics textbooks for elementary first grade. We analyzed the degree of difficulty and familiarity in terms of words and the structure, length, and expression in terms of sentences. The results show some causes that lead the first graders to the difficulty. In more detail, we found 108 difficult words and 6 unfamiliar words for the first graders. And it is noticed that the textbooks contain 37 compound sentences, 727 complex sentences, and 38 compound-complex sentences. They also contain 237 long sentences that are composed of 9 words or more, 168 sentences that assign two activities or more, and 52 sentences that contain three nouns or adjectives or more successively. Based on these results and discussions, we suggested several implications for writing mathematics textbooks for the lower grades in elementary school.

• The Korean Journal of Physiology and Pharmacology
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• v.17 no.6
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• pp.479-484
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• 2013

Given the CYP3A4 and CYP3A5's impact on the efficacy of drugs, the genetic backgrounds of individuals and populations are regarded as an important factor to be considered in the prescription of personalized medicine. However, genetic studies with Korean population are relatively scarce compared to those with other populations. In this study, we aimed to identify CYP3A4/5 polymorphisms and compare the genotype distributions among five ethnicities. To identify CYP3A4/5 SNPs, we first performed direct sequencing with 288 DNA samples which consisted of 96 Koreans, 48 European-Americans, 48 African-Americans, 48 Han Chinese, and 48 Japanese. The direct sequencing identified 15 novel SNPs, as well as 42 known polymorphisms. We defined the genotype distributions, and compared the allele frequencies among five ethnicities. The results showed that minor allele frequencies of Korean population were similar with those of the Japanese and Han Chinese populations, whereas there were distinct differences from European-Americans or African-Americans. Among the pharmacogenetic markers, frequencies of $CYP3A4^*1B$ (rs2740574) and $CYP3A5^*3C$ (rs776742) in Asian groups were different from those in other populations. In addition, minor allele frequency of $CYP3A4^*18$ (rs28371759) was the highest in Korean population. Additional in silico analysis predicted that two novel non-synonymous SNPs in CYP3A5 (+27256C>T, P389S and +31546T>G, I488S) could alter protein structure. The frequency distributions of the identified polymorphisms in the present study may contribute to the expansion of pharmacogenetic knowledge.

• The Journal of the Korea Contents Association
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• v.12 no.10
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• pp.555-562
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• 2012

Due to the burgeoning Korean musical industry, the needs of professional man power as well as the quality and quantity increase in educational institutions are on the rise. The curriculum for art education comprises through school education programs in which embody the artists' self-growth and self-realization. The field of arts simply could not be executed with only techniques but through the theory and educational course, the artist is able to clearly express and communicate their genuine desires. Therefore, Korean musical education could not conform to shortsighted trends or be used as an instant tool for increasing competitiveness among universities but make an effort to provide good quality curriculum for the purpose of producing talented actors. Furthermore, the curriculums should build a sincere trust and give confidence in which receiving a cultural education before choosing a career path is not getting behind ahead of becoming an actor with practical training and knowledge. In order to do so, it is necessary for each university to have more systematical management and administration structure that enable students to build promising future even after graduation through more effective educational courses and strong network. As a result, the competitiveness of the university would rise due to producing talented actors and the quality of musical industry would further improve as well.

• Journal of Digital Convergence
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• v.16 no.5
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• pp.391-398
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• 2018

Analyzing the shortcomings and shortcomings of the film based on the Webtoon and the artistry as a popular artwork at the time when the filming of the webtoon is becoming the main trend of the Korean film, it is an analysis of the present state of the Korean film industry, Will be an indicator for. The present generation of young people who do not have the experience and knowledge of popular arts and culture that handed down a small number of high-quality arts by reflecting current literary, art, history, and popular consciousness are concentrating only on instinctive emotion, It is regrettable that it is consistently followed by follow-up and follow-up unconditionally. In this study, we will examine the methodology of the ideal webtoon filmization process by analyzing the structure and industry analysis of Webtoons, and analyzing the weaknesses in the transition process to the movie format. The essence of communicating with audiences will be unchanged even in the rapid change of media and technology. In the setting and expression of its essence, it is based on the humanistic authenticity mentioned above, the avant garde internal necessity of the artist seeking ideal, And the reflection of the original character of high-class culture that creates newness can be considered as a proposition that can include artistry in popular culture.

• Journal of the Korea Concrete Institute
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• v.29 no.4
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• pp.389-397
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• 2017

Friedel's salt is an important product of chemical adsorption between cement hydrate and chloride ions because it contains chlorine in its structure. When cement reacts with water in the presence of chloride ions, the $C_3A$ phase, and $C_4AF$ phase react with chloride to produce Friedel's salt. If chloride ions penetrate into concrete from external environments, many calcium aluminate hydrates, including AFm, can bind chloride ions. It is very important, therefore, to investigate the chloride binding isotherm of $C_3A$ phase, $C_4AF$ phase, and AFm phase to gain a better understanding of chloride binding in cementitious materials. Meanwhile, the adsorption isotherm can provide us with the fundamental information for the understanding of adsorption process. The experimental results of the isotherm can supply not only the quantitative knowledge of the cement-Friedel's salt system, but also the mechanism of adsorption and the properties of their interactions. The purpose of this study is to explore the time dependant behaviors of chloride ions adsorption with $C_3A$, $C_4AF$ and AFm phases. The chloride adsorption isotherm was depicted with Langmuir isotherm and the adsorption capacity was low in terms of the stoichiometric point of view. However, the chloride adsorption of AFm phase was depicted with Freundlich isotherm and the value was very low. Since the amount of the adsorption was governed by temperature, the affecting parameters of isotherm were expressed as a function of temperature.

• Journal of The Korean Association For Science Education
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• v.37 no.1
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• pp.215-223
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• 2017

This study aims to find an effective way to present essential science concepts in national science curriculum through international comparisons. Next Generation Science Standard (US), Ontario Science Curriculum (Canada), Australia Science Curriculum, and British/English Science Curriculum were selected for comparison. In science curriculum documents, these countries used terms such as 'Key ideas,' 'Big ideas,' 'Key concepts,' 'Disciplinary core ideas.' and 'Fundamental concepts' to present essential concepts of science. This study reviewed the characteristics of the meaning, the status, and the role of essential concepts country by country. The result shows essential concepts have been used with different meanings and statutes in each case. Furthermore, various roles were performed through essential concepts in order to organize their science curriculum. From these foreign nation's cases, this study proposes several ways to present essential science concepts based on results. First, interdisciplinary integrated concepts were needed to organize an integrated science curriculum. In science curriculum documents of the United States, Canada, Australia and England, two types of terms were used in order to structuralize an integrated science curriculum. Second, essential concepts should include concepts related with function and value as well as scientific knowledge. Third, essential concepts need to be presented in such a way as to show specific contexts. Therefore, selecting appropriate contents and structure are needed to be able to improve the way to present essential concepts in Korea's educational environment.