• Korean Journal of Heritage: History & Science
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• v.52 no.3
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• pp.112-129
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• 2019

This study investigates the influence and implications of the supervised process of production of flower vessels (花器) in 1411. The type, the production method, and the purpose of flower vessels (花器) were determined based on the workshops appearing in King Sejong-Sillok, Chiriji ("世宗實錄" "地理志") and Gyeongsang-do Chiriji ("慶尙道地理志"), considering articles excavated from Sangju kiln sites. In addition, the implications and the starting point of production of flower vessels (花器) in the Joseon Dynasty were identified. During the Joseon Dynasty, an effort was made to reorganize the government offices, to align ritual systems in the early 15th century. Preparation for rituals, preparation of supplemental utensils used in ancestral rites (祭器), the construction of architecture related to the Royal Family, and the production of weaponry (武器) were supervised. In 1411, flower vessels (花器) had a preferred supervised process of production as well, which means being recognized as a subject of maintenance for the Joseon Dynasty's aims. Flower vessels (花器) had been produced using grayish-blue powdered celadon (粉靑沙器) as flower pots (花盆), and as celadon flower pot-support (花臺), at Sangju kiln sites in particular, since 1411. Interestingly, products had been manufactured in royal kilns as well as in a few other kilns similar to the supervised process of production of flower vessels (花器) in the middle of the 15th century. It means that this effected the Gyeon-yang (見樣) supervised process of flower vessel (花器) production in 1411. At that time, the Joseon Dynasty used Gyeon-yang (見樣) for imperial gifts for the Ming Dynasty and on separate manufactured articles to ensure the standards of production. Gyeon-yang (見樣) affected the production of ceramic utensils used in ancestral rites (祭器), and government officials in Saongwon (司饔院) supervised the production of ceramics for the Royal Family year after year. In sum, it was flower vessels (花器) using Gyeon-yang (見樣) that provided precise production rules to supervise the process of production in 1411.

• Composites Research
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• v.32 no.3
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• pp.148-157
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• 2019

In this study, $C_f/SiC$, $SiC_f/SiC$ and $C_f-SiC_f/SiC$ ceramic composites reinforcing carbon fiber, SiC fiber and hybrid fiber were fabricated by hybrid TGCVI and PIP process. After the thermal shock cycle, 3-point bending and Oxy-Acetylene torch test, their mechanical behavior, oxidation and erosion resistance were evaluated. The $C_f/SiC$ composite showed a decrease in mechanical property along with increasing temperature, a pseudo-ductile fracture mode and a large quantity of erosion. The $SiC_f/SiC$ composite exhibited stronger mechanical property and lower erosion rate compared to the $C_f/SiC$, but brittle fracture mode. On the other hand, hybrid type of $C_f-SiC_f/SiC$ composite gave the best mechanical property, more ductile failure mode than the $SiC_f/SiC$, and lower erosion rate than the $C_f/SiC$. During the Oxy-Acetylene torch test, the $SiO_2$ formed by reaction of the SiC matrix with oxygen prevented further oxidation or erosion of the fibers for $C_f-SiC_f/SiC$ and $SiC_f/SiC$ composites particularly. In conclusion, if a hybrid composite with low porosity is prepared, this material is expected to have high applicability as a high temperature thermo-structural composite under high temperature oxidation atmosphere by improving low mechanical property due to the oxidation of $C_f/SiC$ and brittle fracture mode of $SiC_f/SiC$ composite.

• Journal of the Korean Institute of Landscape Architecture
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• v.47 no.3
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• pp.39-48
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• 2019

This research is based on the analysis of in-depth interviews of designers who participated in the design of the Yeonnam-dong section, which was completed in 2016. The case study site has received many domestic and foreign awards and is receiving very positive reviews from actual users. 53 concepts were derived from the open coding of the ground theory methodology. Thirty-four higher categories incorporated the concepts and 18 higher categories that reintegrated them. Later, the six categories of the ground theory were interpreted as the paradigm, and it was determined that the aspects of 'will of client' and 'work efficiency', 'site resources' and 'field manager's specialty' were the categories that had the greatest positive impact on the park construction. The key category of this park's construction was interpreted as "a park-construction model with active empathy and communication." The results of the study and are linked to the following research proposals. First, the need to improve the trust between the client and the landscape designer and the need to improve the customary administrative procedures; second, the importance of the input of landscape experts into the park construction process; third, the importance of all efforts to develop the design; fourth, the importance of on-site circular resources and landscape preservation; and fifth active social participation to increase the opportunity. This study, which seeks to grasp the facts that existed behind the park's construction, which received excellent internal and external evaluations, and has a qualitative, objective and structural interpretation of the social network related to the park's construction, in contrast to the conventional quantitative post-evaluation. It is expected that the administration and system improvements related to landscaping will be further improved through the continuation of in-depth post-evaluation studies.

• Korean Journal of Ecology and Environment
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• v.51 no.4
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• pp.311-321
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• 2018

The purpose of this study is to investigate effect of stream channel naturalness on ecological health by using environmental factors and Fish Assessment Index (FAI) in the Han River of South Korea. These samples and data have been released from the research project titled Stream/River Ecosystem Survey and Health Assessment, which was conducted in 444 sites in the Han river watershed from 2008 to 2016. All samples were classified into five groups according to a degree of morphological changes of stream. Water chemistry analyses indicated a decline in water quality by decreasing stream channel naturalness, it is assumed that channelized stream was vulnerable to aquatic pollution compared to the natural meandering stream. In the result of frequency of dominant species, sensitive species and insectivore such as Zacco koreanus, Rhynchocypris kumgangensis and Pungtungia herzi were frequently dominated in the natural meandering stream while tolerant species and omnivores such as Carassius auratus and Cyprinus carpio were more dominated in the channelized streams. The FAI in the channelized stream shows decline to average of $46{\pm}25$ compared with that of the natural meandering stream ($80{\pm}20$). The decrease in FAI was highly influenced by changes in matrixes of fish assemblage structure such as number of sensitive species (M3), portion of omnivores (M5) and insectivores (M6). Moreover, annual average FAIs from 2008 to 2016 were significantly correlated with water chemistry, especially TN, TP and BOD ($r^2=0.59$, p<0.0001). Taken together, all the results suggest that the stream channelization could negatively impact on the water quality and fish assemblage structure, leading to degradation in aquatic ecosystem health.

• The Korean Journal of Archival Studies
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• no.35
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• pp.3-40
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• 2013

Establishment and expansion of a FOI regime is a fundamental basis for modern democracy. Informed decisions and supports by the people are critical to establishment of democratic institutions and policies. The best tool to make informed decisions and to ensure accountability is the FOI. For effective FOI, good records management is necessary requirement. This paper observes and analyses the development of the FOI in the U.S., the Open Government policy, and the government records management reforms under Obama Administration to search viable solutions for Korean FOI and public records management reforms. Major revisions and advancement of the FOIA in the United States are examined, especially the revision of the FOIA as the OPEN Government Act of 2007. The FOIA revision enhanced greatly the freedom of information in the U.S. including the establishment of an independent FOI ombudsman by the Congress. The paper also discusses the Presidential memoranda on the Open Government and the FOI by President Obama, the following directives, Presidential memorandum on government records management and the Government Records Management Directive. Major contents of the directives, plans, and achievement are summarized and analysed. Finally, this paper compares the government records management reforms under former President Roh Mu Hyun with the Obama's reform drive. The comparison found that major difference in the "top-down" government records reforms are the difference in democratic institutions such as weak congressional politics, strong bureaucratic obstacles, and relatively weak social and professional supports for the reforms in Korea, while these reforms were similar in terms that they were driven by insightful political leaders. Independent FOI ombudsman and national records administration are necessary for such democratic reforms.

• Journal of Intelligence and Information Systems
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• v.25 no.1
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• pp.127-137
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• 2019

Recidivism prediction has been a subject of constant research by experts since the early 1970s. But it has become more important as committed crimes by recidivist steadily increase. Especially, in the 1990s, after the US and Canada adopted the 'Recidivism Risk Assessment Report' as a decisive criterion during trial and parole screening, research on recidivism prediction became more active. And in the same period, empirical studies on 'Recidivism Factors' were started even at Korea. Even though most recidivism prediction studies have so far focused on factors of recidivism or the accuracy of recidivism prediction, it is important to minimize the prediction misclassification cost, because recidivism prediction has an asymmetric error cost structure. In general, the cost of misrecognizing people who do not cause recidivism to cause recidivism is lower than the cost of incorrectly classifying people who would cause recidivism. Because the former increases only the additional monitoring costs, while the latter increases the amount of social, and economic costs. Therefore, in this paper, we propose an XGBoost(eXtream Gradient Boosting; XGB) based recidivism prediction model considering asymmetric error cost. In the first step of the model, XGB, being recognized as high performance ensemble method in the field of data mining, was applied. And the results of XGB were compared with various prediction models such as LOGIT(logistic regression analysis), DT(decision trees), ANN(artificial neural networks), and SVM(support vector machines). In the next step, the threshold is optimized to minimize the total misclassification cost, which is the weighted average of FNE(False Negative Error) and FPE(False Positive Error). To verify the usefulness of the model, the model was applied to a real recidivism prediction dataset. As a result, it was confirmed that the XGB model not only showed better prediction accuracy than other prediction models but also reduced the cost of misclassification most effectively.

• Journal of The Korean Association For Science Education
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• v.39 no.1
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• pp.13-33
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• 2019

The purpose of this study is to clarify the possibility of the character education and the concrete implementation process in the field of science education in accordance with the social demand for character education. Based on this purpose, the researchers tried to understand the specific character elements appearing in various science learning situations and to understand the qualities of each specific character elements that can be emphasized through science learning and the aspect of expression process in related learning situations. The researchers selected 11 students from the 7th and 8th graders in Seoul and developed and applied the 'Become a Science Teacher' mentor program in 2014 and 2015. Data collection was conducted through class recordings, mentor teachers' and assistant teacher's journal, artifacts, student journals, student portfolios, class listeners' essays for science class and analyzed qualitative data collected through constant comparison method. According to the result, we extracted 11 character elements and reorganized them into 16 specific character elements revealed in various learning situations based on the relationship between each character elements. The results of the study are eight specific character elements that can be emphasized through science learning and related learning situations. The eight specific character elements are 'responsibility for teaching behavior due to hierarchy of scientific knowledge structure, communication for forming scientific concept, empathic concern based on science learning experience, cooperation for promoting rationality of inquiry method, positive perception of scientific endeavor, respect for scientists' attitudes toward research, confidence in future scientific research, persistence in trial and error'. Based on the results of this study, we proposed the research methods of character in the field of science education in the future.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.2
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• pp.30.1-30.1
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• 2018

일제 강점기를 지난 후 광복을 맞았지만, 전란의 폐허 속에 개설된 대학의 천문학과의 관측 시설들은 전문한 상태였다. 필자가 학부 재학 중이던 6-70년대까지도 시 시공(時空)의 흐름은 필요한 것을 직접 만들어 사용할 수밖에 없는 시대로 몰아가고 있었다. 당시를 회고 하며 지금까지 걸어 온 "천문기기 제작 연구의 삶"을 회고하고자 한다. 대학 재학 시절 교수님의 도움으로 막스토브 망원경을 제작하고, 40cm 카세그레인 망원경 등 광학계의 원리와 특성연구를 통해 부품 조립을 수행할 수 있었다. 태양 흑점관측을 위한 10cm 굴절 망원경의 투영시설을 고안하여 6개월 동안 관측하였지만. 석사 논문을 위해 광전측광 관측시스템을 제작하여 식쌍성 관측을 수행하였다. 그 결과 한국의 시설로 UBV 광도곡선 완성하여 1975년 가을 천문학회에서 발표하였다. 1976년 2월 국립천문대 천문계산연구실에 발령 받고 역서편찬 업무를 담당하면서 소백산 60cm 망원경 최종 설치를 끝내고, 천문대(현 역삼동 과총회관 빌딩) 옥상에 2m 규모의 목재 돔을 설계 제작하고 일반인들을 위한 대중천문 활동을 시작하였다. 재직 중에 항상 한국의 열악한 천문시설의 상황을 실감하고 20대를 마감하면서 퇴직하여 "한국천문기기 연구소"라는 명칭으로 천체 돔을 설계하고, 돔 제작기계를 개발하였다. 망원경만 보관 중인 국내 4개 대학에 돔을 납품 한 후 연세대학교 천문대의 직경 6m 스텐레스 돔을 제작하였다. 아울러 연세대 천문대 60cm망원경을 설치하면서 이 곳에 입사하여 관측 장비개발 연구와 관측에 전념하게 되었다. 재직 기간 중 대학의 배려로 카나다 국립천문대(DAO) 방문연구원으로 1.8m 망원경으로 식쌍성들의 분광관측을 수행하여 시선속도곡선을 완성하였고, 체류 중에 스텝들과 국내에서 사용할 60cm용 첨단 분광기를 설계하였으나 대학에 재원이 없어 제작을 못한 아쉬움이 남는다. 1989년 2월 충북대학교 천문우주학과에 부임하면서 열악한 상황이지만 교육과 연구 장비로 20cm와 35cm 소형 망원경의 디지털 광전측광시스템으로 간이 천문대를 설치하여 운영하였다. 학과 설립 10 주년(1998년)을 맞아 40cm 망원경과 6m 돔을 설치하여 교내천문대가 완공되었다. 2000년이 되면서 대중 천문활동 을 위해 이동 천문대를 제작하여 4륜 자동차에 견인하여 여러 지역을 찾아 관측과 강연 활동 등 학과의 대중천문 활동의 특성을 살리는 계기를 만들게 되었다. 학과 설립 20주년(2008년)을 맞으면서 충북 진천에 16개 자동분할 개폐식 스릿의 9m 돔 안에 1m 망원경을 원격관측 시설을 완비하여 대학 본부의 기관으로 충북대학교천문대를 개관하고 관측시설을 완비하였다. 우리의 전통적인 세종시대 천문시설은 당대 최대의 시설이지만 당시 유물들이 모두 소실되어 현존하는 것이 하나도 없음은 실로 아쉬움이 큰 것이었다. 누군가는 그 구조, 형태, 원리, 기능, 사용방법 등을 밝히고 복원을 시도해야 할 시급함이 있었다. 문헌을 통해 1991년부터 학부졸업 논문으로 "고천문 의기(儀器) 복원연구" 분야의 발표를 시작하였다. 그 결과를 통해 세종탄신일에 영릉에서 숭모제 행사 후 그 곳에서 수년간 세종시대 고천문의기 한가지씩 작동모델을 복원하여 제막식을 거행하였다, 유물복원 회사 (주)옛기술과 문화 와 함께 팀을 이루어 매년 제작할 종목을 준비하게 되었다. 간의(簡儀)를 복원한 후에는 일성정시의, 소간의, 앙부일구, 정남일구, 석각천문도, 혼천의, 혼상, 각종 해시계 등 매년 지속적으로 복원되어 큰 규모의 야외 전시장이 완성되었다. 작동모델 설계연구팀의 자문과 제작팀과의 팀웍으로 이룬 성과인 것이다. 한번 시작품이 발표된 모델들은 국내 과학관과 박물관, 천문관에서 후속 모델을 설치하였다. 한국천문연구원과 부산 동래읍성 내에 장영실 과학 동산은 간의와 혼상을 비롯한 각종 해시계들을 설치한 큰 규모의 야외 전시장이다. 조선의 명망 높은 유학자들이 인격적인 하늘을 살펴보았던 혼천의와 일만원권에 그려 있는 국보 230호 자명종 혼천시계(일만원권의 그림)의 작동 모델을 제작하였다. 이와 같은 연구 결과들은 석사과정 박사과정을 통하여 더 심층적인 연구들이 발표되었고, 각종 조선(한국)의 천문의기(天文儀器) 연구 자료들은 연구팀들을 통해 중국과 일본 등 해외에서도 발표되었다. 지금까지 복원된 유물들이 완성되기까지는 참여한 많은 연구원들과 제작팀들이 합심하여 각자의 역할을 수행하여 최종 작동모델들이 하나 둘 완성되는 것이었다. 이것은 참으로 보람된 일이었고, 은퇴 후 지금은 재능기부자로서 즐거운 삶을 이어 갈수 있게 되었다.

• Korean Journal of Heritage: History & Science
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• v.53 no.4
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• pp.250-273
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• 2020

The three-story stone pagodas in Hyeon-ri and Hwacheon-ri,Yeongyang Gyeongsangbuk-do are stone pagodas that exhibit the typical style of Unified Silla. The two pagodas are believed to have been built in the mid- and late 9th centuries at the latest, considering the style of the three-story roof stone on top of the double-tier base. This is also confirmed by the reliefs carved at the base and the first-story of the pagoda. The Four Heavenly Kings and the Twelve Zodiacal Animal Deities were first combined in the late 8th century in the stone pagoda at the Wonwonsa Temple Site, and the Eight Classes of Divine Beings was also the most popular carved pagoda reliefs in the 9th century. However, the two Yeongyang stone pagodas are characterized by a combination of the Four Heavenly Kings (1st story), the Eight Classes (top base), and the Twelve Zodiacal Animals (lower base), and the stone used for the pagoda consists of sedimentary rocks of the sandstone family, which comprise most of the geological strata in the Yeongyang area, rather than ordinary granite. The new combinations of the three types of guardian deities and the Eight Classes changed from seated to standing poses is interpreted as an attempt to enhance the Buddhist faith and cultural status of the Yeongyang area, along with the fact that the stone pagoda was built using local natural materials. The Eight Classes of the Yeongyang stone pagoda does not follow the two types of arrangement of the pagodas with the Eight Classes, but some of the deities have been relocated to a new location. Composed of AsuraGandharva on the east side, Naga-Mahoraga on the south, Deva-Garuda on the west, and Kimnara-Yaksa on the north, this form can be classified as a unique 'third layout of the Eight Classes' in the Yeongyang area. Such changes in the shape and posture of the reliefs reflect a new perception of the pagodas. The reason why the Gandharva and Yaksa statues were carved on the east and north sides, respectively, was because they were deemed subordinate to the Four Heavenly Kings, and the fact that the Naga and the Mahoraga were carved on the south side was presumed to have influenced the geographical location of the two pagodas on the northern side of Banbyeoncheon Stream. The Hyeon-ri and Hwacheon-ri three-story stone pagodas inherited the tradition of typical Unified Silla-period pagodas, while also bearing their own new regional characteristics.

• The Journal of Korean Society for Radiation Therapy
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• v.32
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• pp.31-39
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• 2020

Purpose: The aims of this study were to compare the superficial dose with Optically Stimulated Luminescence Dosimeter(OSLD) measurement and Treatment Planning System(TPS) calculation for 6MV-Flattening Filter Free(FFF) energy using HalcyonTM and TrueBeamTM. Materials and methods: Phantom study was performed using the CT images of human phantom. In the treatment planning system, the Planning Target Volume(PTV) was contoured which is similar to Glottic cancer. Furthermore, Point(M), Point(R), and Point(L) were contoured at the iso-center of head and neck region and 5mm bolus was applied to the body contour. Each treatment plans using 6MV-FFF energy from HalcyonTM and TrueBeamTM with static Intensity Modulated Radiation Therapy(IMRT) and Volumetric Modulated Arc Therapy(VMAT) were established with eclipse. To reproduce the same position as the TPS, OSLDs were placed at the iso-center point and 5mm bolus was applied to compare the error rate after the dose delivery. Result: The results of the study using human phantom are as follows. In case of HalcyonTM, the mean absolute error rates of the point dose using the treatment planning system and the dose measured by OSLD were 1.7%±1.2% for VMAT and 4.0±2.8% for IMRT. Also TrueBeamTM was identified as 2.4±0.4% and 8.6±1.8% respectively for VMAT and IMRT. Conclusion: Through the results of this study, TrueBeamTM confirmed that the average error rate was 2.4 times higher for VMAT and 3.6 times higher for IMRT than HalcyonTM. Therefore, based on the results of this study, If we need a more accurate dose assessment for the superficial dose, It is expected that using HalcyonTM would be better than TrueBeamTM.