• Restorative Dentistry and Endodontics
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• v.22 no.1
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• pp.1-33
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• 1997

The objective of this study was to analyze the in vitro and in vivo corrosion products of low and high copper amalgams. The four different types of amalgam alloy used in this study were Fine cut, Caulk spherical, Dispersalloy, and Tytin. After each amalgam alloy and Hg were triturated according to the directions of the manufacturer by means of the mechanical amalgamator(Amalgam mixer. Shinhung Co. Korea), the triturated mass was inserted into a cylindrical metal mold which was 12mm in diameter and 10mm in height. The mass was condensed by 150Kg/cm compressive force. The specimen was removed from the mold and aged at room temperature for about seven days. The standard surface preparation was routinely carried out by emery paper polishing under running water. In vitro amalgam specimens were potentiostatically polarized ten times in a normal saline solution at $37^{\circ}C$(potentiostat : HA-301. Hukuto Denko Corp. Japan). Each specimen was subjected to anodic polarization scan within the potential range -1700mV to+400mV(SCE). After corrosion tests, anodic polarization curves and corrosion potentials were obtained. The amount of component elements dissolved from amalgams into solution was measured three times by ICP AES(Inductive Coupled Plasma Atomic Emission Spectrometry: Plasma 40. Perkim Elmer Co. U.S.A.). The four different types of amalgam were filled in occlusal and buccal class I cavities of four human 3rd molars. After about five years the restorations were carefully removed after tooth extraction to preserve the structural details including the deteriorated margins. The occlusal surface, amalgam-tooth interface and the fractured surface of in vivo amalgam corrosion products were analyzed. In vivo and in vitro amalgam specimens were examined and analyzed metallographically by SEM(Scanning Electron Microscope: JSM 840. Jeol Co. Japan) and EDAX(Energy Dispersive Micro X-ray Analyser: JSM 840. Jeol Co. Japan). 1. The following results are obtained from in vitro corrosion tests. 1) Corrosion potentials of all amalgams became more noble after ten times passing through the in vitro corrosion test compared to first time. 2) After times through the test, released Cu concentration in saline solution was almost equal but highest in Fine cut. Ag and Hg ion concentration was highest in Caulk spherical and Sn was highest in Dispersalloy. 3) Analyses of surface corrosion products in vitro reveal the following results. a)The corroded surface of Caulk spherical has Na-Sn-Cl containing clusters of $5{\mu}m$ needle-like crystals and oval shapes of Sn-Cl phase, polyhedral Sn oxide phase. b)In Fine cut, there appeared to be a large Sn containing phase, surrounded by many Cu-Sn phases of $1{\mu}m$ granular shapes. c)Dispersalloy was covered by a thick reticular layer which contained Zn-Cl phase. d)In Tytin, a very thin, corroded layer had formed with irregularly growing Sn-Cl phases that looked like a stack of plates. 2. The following results are obtained by an analysis of in vivo amalgam corrosion products. 1) Occlusal surfaces of all amalgams were covered by thick amorphous layers containing Ca-P elements which were abraded by occlusal force. 2) In tooth-amalgam interface, Ca-P containing products were examined in all amalgams but were most clearly seen in low copper amalgams. 3) Sn oxide appeared as a polyhedral shape in internal space in Caulk spherical and Fine cut. 4) Apical pyramidal shaped Sn oxide and curved plate-like Sn-Cl phases resulted in Dispersalloy. 5) In Tytin, Sn oxide and Sn hydroxide were not seen but polyhedral Ag-Hg phase crystal appeared in internal space which assumed a ${\beta}_l$ phase.

• Journal of Korean Society of Forest Science
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• v.85 no.2
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• pp.300-308
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• 1996

This study was conducted to identify factors involved in rooting of Japanese larch cuttings. Cuttings were taken every week from June 24th to July 25th before and after the 10th of July which supposed to be best time for cutting. The content of IAA, carbohydrate, nitrogen and inorganic elements such as $Mg^{{+}{+}}$, $K^+$ and $Ca^{{+}{+}}$ within cutting materials were analyzed. After the cuttings were planted, the root development was observed every week. Cuttings of easy-to-root clones were higher in IAA contents than the cuttings of hard-to-root clones at the time of cuttings were taken. There were significant differences in moisture content of cuttings taken on June 24th and July 25th between easy-to-root and hard-to-root clones, however no significant differences in moisture contents were observed between them taken on the 8th and 15th of July which supposed to be the best time for cutting. Inorganic matters and carbohydrate contents of cuttings taken from hedged trees were higher than those of non-hedged trees. The ratios K/C and C/N of cuttings taken from hedged trees were higher than those of non-hedged trees. Cuttings taken from easy-to-root clones showed higher content of carbohydrate and nitrogen than those of hard-to-root clones. The contents of inorganic elements, such as $Mg^{{+}{+}}$, $K^+$, and $Ca^{{+}{+}}$ in cutting taken from hard-to-root clones were slightly higher than that of easy-to-root clones. The ratio C/N and K/C of cuttings which were taken from easy-to-root clones have shown a similar trend of carbohydrate and nitrogen. These data indicate that there was no one dominant factor that affect rooting of cutting, but many factors such as contents of IAA, carbohydrate, nitrogen, phosphate, and ratios of C/N and K/C appeared to affect on rooting of cuttings variously. Most of root initials were formed from phloem tissue within one week after cutting, and few were formed from callus tissue. Root primordia were developed from root initials within two weeks after cutting, and most of new roots were developed from root primordia within about five weeks after cutting.

• Journal of the Korean Institute of Landscape Architecture
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• v.39 no.2
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• pp.1-9
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• 2011

This study concerns the Baekje Traditional Garden, one of the open spaces in the Lotte Resort in the Baekje Historical Reappearance Complex, which is part of the comprehensive plan for specific areas in the Baekje cultural area. The Baekje Traditional Garden has historic value, and its excellent garden style influenced the ancient Japanese gardens. This study dealt with three issues: (1) The context in which Lotte Buyeo Resort accepted the Baekje Traditional Garden, particularly the background and process of such; (2) The original form of the Baekje Traditional Garden; and (3) How the Baekje Traditional Garden should be represented in the open space of the resort. Representation is accomplished in two ways: using the structure of the original garden and in the borrowing of elements. For representation using the structure of the original garden, Imrugak was used as the main entrance space, and Wolsunjung was represented from the Ganbuklee remains. In the rear garden are wave watercourses and other garden facilities of the Wanggungri site in Iksan. Borrowing of elements, on the other hand, was accomplished in the plant plan and detailed development. In addition, mountaintops (three mountains and five mountain summits), a clean stream between mountains, and a pine forest are visualized in the garden. This is the representative landscape of the Taoist hermit world that appeared in the Baekje Gilt Bronze Incense Burner and Landscape pattern. The significance of this study is twofold. First, the Baekje Traditional Garden is a fresh trail because there has been no previous research concerning it. Second, while past research concerning traditional spaces focused on the results of representation, this study focused on the process of representation. This means that this research work tried to extend the study concerning the representation of traditional spaces from the conceptual to the practical approach. This study, however, also has its limitations. The authenticity of the representation suggested in this study may be questioned later because efforts have been made to preserve the original Baekje Traditional Garden. In addition, this study should seek a balance between authenticity on one hand and amusement and diversity of experience on the other, because the site is a resort.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.8 no.3
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• pp.125-146
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• 2013

Nowadays, the performance of the mobile game sales is influencing the ranking of game companies listed on KOSDAQ. In the meantime, venture capital companies had focused on online game. Recently, however, they have great interest in mobile games and mobile game companies. In addition, angel investors and accelerators are increasing investment for the mobile game companies. The most important issues for mobile game investor is how to evaluate the mobile game companies and their contents. Therefore, this study derived the evaluation factors for the mobile game company. And research method converged of the opinions of both supply side and demand side of the game industry. Ten professionals who are responsible for the supply of the game industry and CEO group & development experts of game development company were selected for survey in this study. Also ten professionals who are responsible for the demand of the game industry and the investment company were selected for survey in this study. And Delphi technique was performed according to the survey. Management skills, development capabilities, game play, feasibility, operational capabilities has emerged as five evaluation factors to evaluate the mobile game company. And the 20 sub-factors including CEO's reliability were derived. AHP(Analytic Hierarchy Process) theory is applied to analyze the importance of the qualitative elements which were derived by Delphi technique. As a result, the analysis hierarchy of evaluation factors for the mobile game company was created. Pair-wise comparison for each element was performed to analyze the importance. As a result, 'Core fun of the game' (12,2%), 'Involvement of the game' (10.3%), 'Security Reliability' (8.9%), 'Core developers' ability' (7.6%) appeared in order of importance. The significance of this study is offering more objective methodology for realistic assessment and importance of elements to evaluate mobile game company.

• Korean Journal of Hospice Care
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• v.8 no.1
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• pp.13-28
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• 2008

Purpose: This paper aims to examine the subjective structures and types of school age children's perception of death through an investigative study on their perception of death in order to provide a basic material for them to understand death, and develop and carry out an effective death education program. Methods: The study method used the Q Methodology which can investigate the subjective structures and types of school age children's perception of death. For Q-population, 20 school age children were used as subjects for neutral interviews and open surveys, and through documentary research, a total of 132 statements were collected, For Q-samples, 23 statements (Q-samples) were derived through a non-structural method. P-samples were 31 school age children (8-13 year olds), Q-sorting was carried out using Q-cards, and the collected data was analyzed using the PC QUANL program. Results: As a result of the study, children's perception of death was divided into five types. The first type was functional type, characterized by prominent subjective perception regarding the elements of death, such as non-reversibility, universality, non-functionality, and causality. The second was after-life type, characterized by a strong, focus on life after death in one's perception of death, and it included children with Christian background and those who had experienced death in their immediate family. The third was religious type, characterized by a strong belief in being able to still watch over one's family and friends after one's death, resulting in a positive faith in the after-life. The fourth was fearful type, characterized by a deeper fear of death in comparison to other types. The fifth was realistic type, characterized by a strong and positive assent to the perception of good death. Conclusion: The significance of the results of this paper's study to Nursing is as follows. In terms of understanding the subjectivity of school age children's perception of death in nursing practice, and understanding the compositional elements of death presented with strong emphasis in existing literature and studies, the results will expand these understandings and allow us to understand the level of perception in school age children regarding the definition of death, after-life, and good death, be utilized as useful material in developing an effective death education program for them according to their type characteristics, and become the fertilizer for enabling the children to live a proper life and preventing the tendency to make light of death that occur in adolescence and the spread of suicides. In terms of nursing theory, the description and examination of the subjective structures and the characteristics of the different, types of school age children's perception of death can be utilized as useful material for building a model of school age children's perception of death, and be further used for teaching respect for life. In terms of nursing research, the results can contribute to research describing the effects of nursing intervention strategies and developing tools for providing psychosocial nursing in terms of giving school age children a positive perception of death according to their types as well respect for life.

• Journal of Korean Home Economics Education Association
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• v.29 no.3
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• pp.141-160
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• 2017

At present, the whole world is characterized by openness, cooperation and integration as a society with information and the world, and it requires creative talents for this. The competitiveness of the nation depends on the cultivation of creative talents. It demands anthropological value by improving the competitiveness of the nation through cultivating creative talents to share and care, not to cultivate creative talents for personal desires and accomplishments. The purpose of this study is to develop a teaching - learning process to develop integrated creative talents by applying the characteristics of integrated education curriculum at the base of the 2015 revised curriculum. To do this, we first extracted the content elements of the Clothing Life area of the revised curriculum from the 1st to 2015 and the contents of the Clothing Life area of the technology and home Economics textbooks to which the 2009 revision curriculum was applied. Five topics were extracted according to content selection criteria And The Theme of 'The selection and management of clothing' was selected. Researcher developed a integrated thematic instruction Home Economics Education Clothing Life teaching - learning process (hereinafter referred to as "the process") focused on the theme of 'selection and management of clothing'. The Process was composed of 5 basic classes [basic inquiry - content 1 - content 2 - depth study - application]. The process considers integration within the curriculum and interdepartmental integration, and aims to improve the personality, creativity, and problem solving ability of consideration and sharing in the course of the integrated class. In detail, the curriculum goals of the home Economics Education curriculum and ITI goals are presented separately in the curriculum developed for each process. At the stage of the class, the element of creativity and the element of personal education were exposed and applied to the class. In Korea, new curriculum has been revised and announced from time to time, making it difficult for the teacher to carry out the class in accordance with the paradigm of change. Home curriculum is closely related to real life, so it is an appropriate subject for an integrated subject. It has the educational significance of the subject in that it allows students to integrate the creative and personal elements that are limited in other subjects. ITI process will be helpful to teachers who need to implement the 2015 revised curriculum in which the theme-centered integrated home Economics education teaching-learning process is newly introduced. It is necessary to follow - up research to verify the effectiveness of how to improve students' problem - solving ability and cultivate creativity.

• Journal of the Korean Society of International Agriculture
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• v.30 no.4
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• pp.347-356
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• 2018

Genetically modified (GM) crops have been increased continuously over the world and concerns about the potential risks of GM crops have also been increasing. Even though GM crops have not been cultivated commercially in Korea, it should be necessary to develop the safety assesment technology for GM crops. In this study, we investigated the influence of heading date difference on gene flow from GM to non-GM rice. In the experimental plot design, The PAC GM rice was placed in the center as a pollen donor and non-GM rice were placed in eight directions as pollen receivers. Five pollen receiver rice cultivars were Unkawng, Daebo, Saegyejinmi, Nakdong-byeo, and Ilmi which had different flowering times. A total of 266,436, 300,237, 305,223, 273,373, and 290,759 seeds were collected from Unkawng, Daebo, Saegyejinmi, Nakdong, and Ilmi, respectively, which were planted around PAC GM rice. The GM${\times}$non-GM hybrids were detected by repeated spraying of herbicide and PAT immunostrip assay. Finally, the hybrids were confirmed by PCR analysis using PAC gene specific primer. The hybrids were found in Nakdong-byeo which had the same heading date with PAC GM rice. The hybridization rate was 0.0007% at Nakdong-byeo plot. All of GM${\times}$non-GM hybrids were located within 2 m distance from the PAC GM rice zone. The physiological elements including rice heading date were found to be important factors to determine GM?rice out crossing rate with GM rice. Consideration should be taken into for many factors like the physiological elements of field heading date of rice cultivars to set up the safety management guideline for prevention of GM rice gene flow.

• 기호학연구
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• no.54
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• pp.93-117
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• 2018

The process of creating Hunminjeongeum described in Haerye version of Hunminjeongeum shows a rule of signification by which a signifiant represents a referent. In this article, I will suggest two types, the mythical and the anti-mythical, that affect the iconic relation between signifiant and referent, and consider how they are realized in Hunminjeongeum. The mythical type is shown as Yin-Yang and the Five Elements Theory and Three Elements Theory of Heaven, Earth and Man dominating the thought of intellectuals at that time. It had became mythos, that is the object of absolute belief, by connecting with the power of King at that time. It is very metaphysical and involves a kind of grand narrative. It is also the voice from the past in time and from China in space. It is reflected in Hunminjeongeum's letter system intactly. Meanwhile, the anti-mythical type also affects the creation of Icon in Hunminjeongeum. Even if Hunminjeongeum had been created from King Sejong's project, its intention seemed to be educational and practical. That is the problem of that time, not of past time, and for common class, not for ruling class. It can be considered as logos in that it had been planned and processed at a real-life situation at that time. Some arguments between King Sejong and liege Choi, Manri about the validity of Hunminjeongeum also show that the creation of Hunminjeongeum had involved the problem of critical logos. Above all, in that referents of Icons of Hunminjeongeum are the figures of human vocal organs, we can suggest that these Icons also implied an Indexicality implying actual connection between voice and body. It can be considered as a deconstrucion of metaphysics and grand narrative that had been dominated by foresaid mythical type. Hereafter, from time when Hunminjeongeum have been widely used, mythos of metaphysics and grand narrative that had dominated Hunminjeongeum have been deconstructed and Hunminjeongeum has become to realize its potential competence of pragmatic sign system for the convenience of common people. Therefore, I expect that the cultural potentiality of Hangul today can be realized by such tendency of logos incessantly deconstructing mythos, that is one direction of mythosemiosis.

• The Journal of Korean Philosophical History
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• no.58
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• pp.201-243
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• 2018

Understanding the theory of how a religion accepts the perspective on death is a prerequisite to grasp the identity and characteristics of such religion. Furthermore, contemplating the perspective on death, itself has a significant meaning as the contemplation provides an insight on how religion has, currently is and how it would influence the practical life of the human race. This current study compares and analyzes the perspective on death accepted by New Religions of Jeungsan, Confucianism and Taoism. By comparing the perspectives on death, this study seeks to conclude the similarity and discrepancy of New Religions of Jeungsan, Confucianism and Taoism. The objective of this study is to summarize the religious characteristic and identity of New Religions of Jeungsan, and the social role of New Religions of Jeungsan. How does New Religions of Jeungsan preach afterlife? This question implies varieties of questions including: In what shape or form does human exist in afterlife?; Does human maintain their original identity in afterlife?; What happens to relations with family members in afterlife?; What is one's role in afterlife, and what would one experience in afterlife? or Does soul transmigrate or are reborn? This current study compares the answers to these questions one by one with Confucianism and Taoism.In general, this current study was conducted with a non-religious methodology. Death can be explained in three different domains: the psychological domain explaining the individual psychological awareness upon encountering death; the philosophical-religious domain explaining the death through the philosophical understanding of the human concept; and the socio-cultural domain explaining death through the social ceremonies upon death.This current study focuses on the philosophical domain of the perspective on death accepted by New Religions of Jeungsan, with a comparison of the socio-cultural significance. To understand the perspective on death preached by New Religions of Jeungsan, It is indispensable to explain the five key elements of Hon(魂), Baek (魄), Shin(神), Young(靈) and Seon(仙) that construe death. The perspective on death preached by New Religions of Jeungsan imposes a multi layer of acceptance and overcoming. This current study complements the problems and limits of previous studies by comparison with Confucianism and Taoism. Throughout this process, this current study intends to highlight the key elements of the perspective on death preached by Deasunjinrihoe, and identify the aspects of each key element. With the sophisticated discussion of the perspective on death provided by New Religions of Jeungsan with clarity, this current study will provide grounds for future studies to extract, in detail, the aspects of the perspective on death preached by New Religions of Jeungsan, in further subjects including: discussions on death such as rituals for death, treatment of bodies, funerals, educating death, euthanasia, or suicide; discussions on the existence of hell; discussions on psychological aspects of ones who encounter death; or discussions on rebirth of those who died during the creation era. This current study will provide an overview on what kind of perspective on death does those who are faithful to New Religions of Jeungsan have and currently are living their life with.

• Journal of Korean Elementary Science Education
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• v.41 no.4
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• pp.740-753
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• 2022

This study was conducted to develop and apply an out-of-school STEAM program model based on Social-Emotional Learning (SEL) for underprivileged students in the lower grades. To this end, a STEAM program based on SEL was developed, with the following characteristics. First, by integrating traditional STEAM learning elements and SEL elements, a structured program was designed with consistent stages, including mindfulness meditation→present an authentic situation→creative design→emotional experiences→reflection. Second, the program was structured so that elementary school students could develop mathematical thinking and scientific inquiry skills in problem-solving situations in daily life. Third, the detailed themes for each STEAM program involved storytelling-based problem situations, as well as activities centered on play and sympathy to reflect the educational needs of underprivileged students. From these characteristics, a total of five programs were developed and applied to 16 teachers and 354 lower-grade elementary school students in 16 community children centers nationwide. The results were as follows. First, while students' satisfaction with the STEAM program was 4.16, there were no significant differences in STEAM satisfaction according to gender. Second, while all students' interest and self-efficacy, which was one of sub factors of STEAM attitude, were significantly improved, no significant difference was seen in STEAM attitudes according to gender. Third, although students' SEL competencies were not significantly improved, relationship skills, which were among the sub factors of SEL competencies, were significantly improved, and there were no significant differences in SEL competencies according to gender. From these results, a discussion on the effect of the out-of-school STEAM program for underprivileged students and directions for follow-up studies was suggested.