• The Journal of Engineering Geology
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• v.16 no.4 s.50
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• pp.337-349
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• 2006

Seven hundred and fifty one fractures of the rhyolitic tuffaceous rock masses were mapped using 6 scanlines placed on rock slope exposures that were within 8.02 km of Busan-Ulsan highway. These data were analyzed to find the number of fracture sets that exist in the rock slopes and the probability distributions of orientation, spacing, trace length and fracture size in 3-D for each of the fracture sets. All the fracture set orientation distributions exhibit high variability. The Fisher distributions were found to be unsuitable to represent the statistical distribution of orientation for most of the fracture sets. The probability distributions, gamma, exponential and lognormal were found to be highly suitable to represent the distribution of spacing and semi-trace length of fracture sets. In obtain-ing these distributions, corrections were applied for sampling biases associated with spacing and trace length. The generated fracture system in 3-D was used to make predictions of fracture traces for each fracture set on 2-D win-dows. Developed stochastic 3-D fracture network for the rock mass was validated by comparing statistical proper-ties of the observed fracture traces on scanlines with the predicted fracture traces on the scanlines. This exercise fumed out to be successful.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.15 no.1
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• pp.141-154
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• 2012

This study was launched to verify the effective composition of plant species and its management program most suited for the dredged soiled area near Nakdong River Site 14. The improvement methods of planting base and the composition of plants such as silver grass, reed, and some colonies in aesthetic effect were studied. To search the management methods to decrease the confining pressure risen from the burried seeds which would consequently harm the previously seeded plants, experimental construction process was measured on the site. The purpose of this experiment was to figure out which part of the improvement on the plant base has the most significant effect for the revegetation of infertile, dredged soil, to verify the easily seeded, developing plants among seeded plants, and finally, to find the restoration model using plants near the dredged soil around riverside. 8 seeded plants and 23 invaded species were appeared which among the emerged plants, development of Aster yomena MAKINO, Lotus corniculatus var. japonica Regel, Trifolium repens L, and Dianthus longicalyx Miq were proved to be brought up well. Difference risen from the seed composition were not noticeable until 150day since the germination was proceeded mainly by Aster yomena MAKINO. The experimental plot with dredging sand+organic fertilizer method of construction and dredging sand+soil conditioner method showed most development while the effect of the plot with only the soil base of dredging sand stayed low. Another important method for the management of infertile, dredged soil base would be the removal of disturbing species which the experiment showed the tied relationship between the removal of disturbing species and development of seeding plants. Although this study was carried out focused on the Nakdong River Project, the study suggests the general management program that the removal of disturbing species such as Humulus japonicus Sieboid & Zucc. and Pueraria lobata (Willd.) Ohwi in times around rainy season(60days after seedling) would be effective for the easy growth of revegetation plants.

• Journal of Chest Surgery
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• v.31 no.5
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• pp.531-535
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• 1998

In 1964, Abbott and Colleagues published the world's first heterotopic heart transplantation technique in the rat. Their method established circulation by end-to-end anastomoses of the graft's aorta and pulmonary artery to the recipient's abdominal aorta and Inferior Vena Cava(IVC), respectively. In 1966, Tomita et al altered Abbott's technique by employing end-to-side rather than end-to-end anastomoses, thus eliminating the hind leg paralysis that sometimes resulted from Abbott's technique. In order to prevent postsuture hemorrhage (since 7-0 silk suture was the finest available at that time), Tomita's aortic anastomosis was done with double up-and-down continuous suture technique. A single layer continuous anstomosis effected the pulmonary artery-IVC anastomosis. The availability of Nylon monofilament suture made it possible for Ono and Lindsey to use a single layer suture technique for the aortic end-to-side anastomosis in their modified rat heart transplantation. We observed survival time between control group and Immunosuppression(Cyclosporine administration, 10mg/Kg${\times}$4 times postoperatively) group after heterotopic heart transplantation in the rat model. The cyclosporine adminstration group survived longer than the control group, thus we concluded that cyclosporine was based on Immunosuppressive drugs.

• (The)Study of the Eastern Classic
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• no.68
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• pp.237-281
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• 2017

This research aimed at investigating Kim Gyoshin's recognition on Korean traditional ideology and harmony of Christian idea and traditional idea through the writing and diary in "Bible Joseon". Kim Gyoshin expressed positive interest in Korean traditional idea and traditional religion, and intended to localize Christian belief through communicating with them. He expressed infinite respect for national cultural asset of Buddhism, intending to research Korean Buddhism. He paid utmost attention to Confucianism among traditional ideas. He had a strong affection for learning(好學), benevolence(仁義), conscience(良心) of Confucianism as patriotic character. He calmly practiced caution and solitary(愼獨) of sincere(誠), solemnity(敬) of Confucianism through his life, however he chose Christian belief by accepting atonement belief realizing human sinful nature fundamentally inherent in human being. He personally respected Confucius and lived after the model of him, however he searched the spirit of life to renew the people from Christianity. Academically, he respected Confucius, and believed in Jesus in religion. He highly evaluated the attitude of patriot(志士), which highly regarded the academic attitude of learning(好學) and benevolence(仁義), in this regard, criticized blind and non-intellectual belief. He had an open attitude toward Korean traditional idea with no prejudice. As human individuals have their own inherent moral value, he viewed that each people would have their inherent ethnicity and mission. He considered that Korean Peninsula where contradiction and yoke of the world history are inherent is the center of East Asia that would purify injustice of the world. He viewed that Korean people had owned their original good heart[仁] even before Buddhism and Confucianism had been transmitted to the country. He determined that Korean people were good people, who received goodness from the heaven. However, while Uchimura created Japanese style Christianity by adapting Japanese knighthood to Christian idea, Kim Gyoshin lacked sharp critical mind regarding how to establish Korean style Christianity by adapting which of Korean traditional idea to Christian idea.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.6
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• pp.553-581
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• 2022

Shortly after tunnel boring machine (TBM) was introduced in the tunneling industry, the use of TBM has surprisingly increased worldwide due to its performance together with the benefit of being safely and environmentally friendly. One of the main cost items in the TBM tunneling in rock and soil is changing damaged or worn cutters. It is because that the cutter change is a time-consuming and costly activity that can significantly reduce the TBM utilization and advance rate and has a major effect on the total time and cost of TBM tunneling projects. Therefore, the importance of accurately evaluating the cutter life can never be overemphasized. However, the prediction of cutter wear in soil, rock including mixed face is very complex and not yet fully clarified, subsequently keeping engineers busy around the world. Various prediction models for cutter wear have been developed and introduced, but these models almost usually produce highly variable results due to inherent uncertainties in the models. In this study, a case study of design and construction of disc cutter change is introduced and analyzed, rather than proposing a prediction model of cutter wear. As the disc cutter is strongly affected by the geological condition, TBM machine characteristic and operation, authors believe it is very hard to suggest a generalized prediction model given the uncertainties and limitations therefore it would be more practical to analyze a real case and provide a detailed discussion of the difference between prediction and result for the cutter change. By doing so, up-to-date idea about planning and execution of cutter change in practice can be promoted.

• Korean Journal of Materials Research
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• v.28 no.11
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• pp.663-670
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• 2018

H13 tool steels are widely used as metallic mold materials due to their high hardness and thermal stability. Recently, many studies are undertaken to satisfy the demands for manufacturing the complex shape of the mold using a 3D printing technique. It is reported that the mechanical properties of 3D printed materials are lower than those of commercial forged alloys owing to micropores. In this study, we investigate the effect of microstructures and defects on mechanical properties in the 3D printed H13 tool steels. H13 tool steel is fabricated using a selective laser melting(SLM) process with a scan speed of 200 mm/s and a layer thickness of $25{\mu}m$. Microstructures are observed and porosities are measured by optical and scanning electron microscopy in the X-, Y-, and Z-directions with various the build heights. Tiny keyhole type pores are observed with a porosity of 0.4 %, which shows the lowest porosity in the center region. The measured Vickers hardness is around 550 HV and the yield and tensile strength are 1400 and 1700 MPa, respectively. The tensile properties are predicted using two empirical equations through the measured values of the Vickers hardness. The prediction of tensile strength has high accuracy with the experimental data of the 3D printed H13 tool steel. The effects of porosities and unmelted powders on mechanical properties are also elucidated by the metallic fractography analysis to understand tensile and fracture behavior.

• Korean Journal of Heritage: History & Science
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• v.41 no.1
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• pp.127-141
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• 2008

This article found that establish of the new study, "Archaeology of Textile", and its process of development based on the Silk Road from China. Archaeology of Textile which is formed by the modern archeology in the 20 centuries developed is a research focused on textile and is required experts knowledge of archaeology, natural science, and history of textile. Textiles are the most difficult to handle of existing antiquities and it is rare to be excavated perfectly. However, the early archaeologists were interested in the Silk Road inconsistently. There were various kinds of silk and embroidery in the center of excavation process. In China, there are still numerous textiles have been excavating from across the country which has leaded to the top level of the textile study in the world. Compare to China, Korea hasn't excavated textile much, and we've been having a difficulty to research with small pieces of textile fabrics. With lack of understanding of textile, it is insignificant to excavate relic such as Chunma-Chong(天馬塚), tomb of king Muryeong(武寧王陵) which has started in-depth studying after 30 years later since it was discovered. Accordingly, a history of archeological textile will be introduced and make sure the possibility of study of excavated textile will make sure through this study.

• Journal of Technologic Dentistry
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• v.41 no.2
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• pp.63-69
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• 2019

Purpose: The purpose of this study is to evaluate the effect of CAD/CAM system milling tool wear on the marginal and internal fit of PMMA implant interim prosthesis three-dimensional manner. Methods: A total of 20 crowns were fabricated with CAD/CAM method. Their designs were unified to first molar of the left maxilla. The Customized abutments were prepared and scanned with on optical model scanner. Five crowns were milled by the newly replaced tool (1st milling), and 15 crowns were milled by 2nd, 3rd, 4th milling tool. The marginal and internal fit of 20 interim crowns were measured using the triple-scan protocol. Results: Statistically significant difference was found between the $1^{st}$ milling group ($51.8{\pm}14.6{\mu}m$) and the $3^{rd}$, $4^{th}$ milling group ($128.6{\pm}43.8{\mu}m$, $146.2{\pm}38.1{\mu}m$, respectively) at the distal margins. In the mesial margins, There was a statistically significant difference between the $1^{st}$ milling group ($63.6{\pm}25.9{\mu}m$) and the $3^{rd}$, $4^{th}$ milling group ($137.2{\pm}25.9{\mu}m$, $186.8{\pm}70.6{\mu}m$, respectively). In the distal line angle, significant difference was found between the $1^{st}$, $2^{nd}$, $3^{rd}$ milling groups and the $4^{th}$ milling group. In the mesial axial wall, significant difference was found between the $1^{st}$ milling group ($52.2{\pm}20.3{\mu}m$) and the $3^{rd}$, $4^{th}$ milling groups ($22.8{\pm}8.8{\mu}m$, $7.8{\pm}5.7{\mu}m$). Conclusion: As a result of the experiment, decrease of the marginal and internal fit was statistically significant as the number of machining cycles increased. In order to produce clinically excellent restorations, it is recommandable to consider the condition of the milling tool wear, when designing the restoration with CAD program.

• Journal of the Korean GEO-environmental Society
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• v.12 no.3
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• pp.55-61
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• 2011

Song-Do international city is the area developed in large-scale land reclamation. Song-Do area consists of reclamation layer, sedimentary layer(loose silt, soft clay and sand alternating) and residual layer from the ground surface. Therefore, using pile foundation is inevitable to build structures safely. In this area, driven PHC piles have been generally constructed in terms of environmental and economic conditions. As a result of analyzing 4 sites in Song-Do district 5 and 7 recently, the method of driving pile has many problems because of existence of rigid soil in sedimentary layer and installation of more than 30m piles. In this case, when installing piles by drive after pre-boring up to appropriate depth, the results of constructability analysis were very good. And in the economic efficiency, although 4% of construction cost rose, it was a very slight increase in comparison with improvement of workability. In the case of the stability, more than 70% compared to the allowable stress of piles was satisfied through the load test. As a result, when PHC piles is installed in Song-Do district, the proper construction method is that piles are located at bearing layer after boring rigid sand layer.

• (The)Study of the Eastern Classic
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• no.57
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• pp.201-229
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• 2014

한국에서의 유가(儒家) 경전의 수용은 삼국시대에 시작되었으며, 이는 신라(新羅)시대 태학(太學) 교육 중의 한 과목이 "상서(?書)"였다는 "삼국사기(三國史記)"의 기록을 통해 알 수 있다. "상서(?書)"는 고대 정치제도 및 정치사상과 매우 긴밀한 관련을 갖는 경전인 까닭에 중국뿐만 아니라 한국에서도 통치자들의 시정방침(施政方針)상의 중요한 근간(根幹)이 되었다. 이러한 연유로 "상서(?書)" 연구를 통해서 경서 내용을 알게 될 뿐만 아니라 그 시대의 정치사상도 알 수 이해하게 될 것이다. 그런데 한국에 있어서 경학 연구는 중국과 달리 전통적 사서오경(四書五經) 혹은 십삼경(十三經)이 아니라 "사서삼경(四書三經)"을 중심으로 전개되었다. 또한 개별 경전에 대한 연구를 기준으로 살펴보면, "사서(四書)"의 경우, 특히 "논어(論語)"에 대한 연구가 집중적으로 이루어졌다. 삼경(三經)의 경우, "주역(周易)"이나 "시경(詩經)"은 이미 많은 연구가 이루어졌으나, 한국에서 "상서(?書)" 연구는 아직 전자만큼 활발히 이루어지지 못하고 있다. 또한 성균관대학교에 발간한 "한국경학자료집성(韓國經學資料集成)"을 살펴보면, 한국 경학 저술 총 145권 가운데 "상서(?書)" 부분이 22권을 차지하고 있다. 즉 거의 6분의 1이 "상서(?書)" 관련 저술이라고 할 수 있다. 본고는 "학술총람"과 공구서(工具書) 전자 시스템에 수록된 1901년부터 2014년 상반기에 이르기까지의 100여 년 동안 한국(韓國)에서 발표된 "상서(?書)" 관련 학술단행본 학위논문 학술지논문 등을 검토하고, 이를 통해 한국에서의 "상서(?書)"학(學) 연구(硏究)를 회고(回顧)하고 또 그 미래를 전망(展望)해 보도록 할 것이다. 전적으로 보면 한국 "상서(?書)"학 연구는 3가지를 포함한다. 첫째는 한국에서 중국 고전 "상서(?書)" 원전(原典)에 대한 탐구(探究)인데 이를 '중국 "상서(?書)" 연구' 라고 칭하였다. 둘째는 조선시대 유학자의 서경 저술을 중점 대상으로 연구하는 것으로 이를 '한국 "서경"학 연구'라고 이름 하였다. 셋째는 한국 이외 다른 나라 학자들의 조선시대 "서경" 저술에 대한 연구이다. 이상 3가지를 모두 대상으로 삼아야 온전한 한국 "상서(?書)"학 연구라고 할 수 있을 것이다. 향후의 연구 방향은 다음 네 가지로 정리할 수 있다: (1) 역본의 연구 (2)학파별 연구 (3)문헌적 연구 (4)경연과 과거시험의 각 나라 비교 연구이다. 한국 "서경"학에 대한 연구를 통해 우리는 조선시대의 사상과 문화 특히 정치사상을 파악할 수 있으며 또한 전통시대 동아시아 각국의 학문 양상까지도 인식할 수 있을 것이다. 요컨대, 아직까지 한국의 학계에서 한국 "서경"학을 중심으로 하여 이러한 측면을 밝히는 연구는 부족한 편이라고 할 수 있겠으며, 그렇기에 연구할 영역이 더욱 많은 셈이라고도 할 수 있는 것이다. 바로 이 연구영역들에 더욱 심혈을 기울여 앞으로 더 깊이 있고 폭 넓은 연구가 진행되기를 기대할 수 있게 되는 것이다.