• 박물관보존과학
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• 제14권
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• pp.61-67
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• 2013

고려시대의 칠기는 10세기 초에서 14세기에 이르는 동안 다양하게 변화하였으며 화려한 전성기를 이루고 독창성이 돋보이는 나전칠기로 발전하게 되었다. 고려나전칠기는 나전과 대모, 금속선등을 이용한 세밀한 문양과 여기에 화려함을 더하는 묘금기법이 특징이다. 금분을 이용해 선묘를 하여 칠기를 장식하는 묘금기법은 회화적 장식적 측면에서 대단히 화려하지만 묘금에 의한 문양표현을 찾아볼 수 있는 유물은 극히 드물고 묘금기법에 대해 참고할 수 있는 문헌자료도 많지 않다. 본 연구에서는 고려시대 칠기의 묘금을 대상으로 미시경적 관찰을 하여 금분의 특징과 교착제, 교착상태 등에 관해 밝히고 고대기술의 복원연구 자료를 제공하고자 하였다. 연구결과 금분의 입자는 불규칙한 방형과 다각형, 삼각형 모양으로 크기가 2 ㎛에서 20 ㎛까지 다양하게 보이며 금분의 입자는 끝이 말려들어가 중첩되어진 부분이 보이고 전체적으로 금분입자는 종이가 구겨진 듯한 형상과 비슷하게 관찰되었다. 이번 연구를 통해서 고려시대 묘금에서 사용된 금분은 금박을 분말상태로 분쇄하여 만든 금분을 묘금에 사용하였다는 것을 보여준다.

• 대한기계학회논문집B
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• 제20권6호
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• pp.1931-1940
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• 1996

The effect of periodic passing wake on the film-coolant flow issuing normally from a flat plate was investigated experimentally. The passing wake was generated by rotating thin circular bars. Depending on the rotational direction the test plate could be simulated as a pressure surface or a suction surface of a gas turbine blade. The phase-averaged velocity components were measured using an X-type hot-wire probe. The Reynolds number based on the free-stream velocity and injection hole diameter was 23, 500 and the velocity ratio which is the ratio of film coolant velocity to free-stream velocity was 0.5. The velocity-triangle induced by the wake was similar to that induced by the one generated at the blade trailing edge. The vertical velocity component induced by the passing wake, which approaches to the suction surface and moves away from the pressure surface, played a dominant role in the variation of the flow field. The variation in the phase-averaged velocity on the pressure surface was greater than on the suction surface, but the turbulence kinetic energy variation on the suction surface appeared larger than on the pressure surface.

• 농업생명과학연구
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• 제43권6호
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• pp.53-57
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• 2009

동양꽃꽂이는 고대에 신에게 헌화한 공화양식으로 좌우대칭의 삼존형식의 엄격한 삼각형의 조형미를 갖추고 있었으며 침봉을 사용하여 꽃을 고정하므로 쉽게 꽂을 수 있었다. 서양꽃꽂이는 이집트시대에 꽃을 연속반복으로 쌓아 올려 원추형의 형태를 이루어 현재 vertical form의 근원으로 보고 있다. 그리이스 시대에는 부드러운 S라인 형식을 주로 사용하였고, 로마시대에는 꽃들의 중심을 풍성하고 화려하게, 갈수록 낮고 가늘며 긴 수평형으로 연결하였다. 페르시아 시대에는 동양의 삼존형식과 비슷한 triangular 조형을 나타내고 있다. 그리고 르네상스 시대에 꽃꽂이도 고전의 바탕위에 기본형이 창조되었으며, 19세기말 동양미술의 온화한 색과 단순미, 사실적 묘사 등에 영향을 받아 20세기 미국을 중심으로 양적 mass에서 공간미학까지 꽃꽂이의 영역이 광범위하게 표현되는 art nouveau 시대로 이어졌다. 서양꽃꽂이는 조형성에 기초를 두는 것은 동양꽃꽂이와 같으나 자연성이 거의 무시되고 실용성에 근거를 삼는 것이 특징이다.

• 대한본초학회지
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• 제34권6호
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• pp.25-32
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• 2019

Objectives : Ephedra regeliana, although similar to the other E. sinica, E. intermedia, and E. equisetina, is not authorized by The Korean Pharmacopoeia and yet has also been imported under the name of 'Ma-Hwang'. The aim of this study was to perform a comparative anatomical evaluation of Ephedrae Sinicae Herba (ESH), Ephedrae Intermedicae Herba (EIH), Ephedrae Equisetinae Herba (EEH) and Ephedrae Regelianae Herba (ERH). Methods : Permanent paraffin-embedded specimens were produced using the paraffin-tertiary butyl alcohol (TBA) method, to visualize their anatomical features via light microscopy. Results : ESH and ERH transverse sections were in the shape of a long ellipse, while those of EIH and EEH were in the shape of a circle. These anatomical characteristics substantiated the results of external morphological examination. The sections revealed that each of the four samples showed significantly different cortexes. The cortex of ESH was wider than two thirds of the section, unlike that of the other samples which was relatively narrow. The xylems of ERH, EIH, and EEH demonstrated interconnectivity with other adjacent xylems, contrary to those in ESH. Therefore, the characteristic development of the xylems over time was used to distinguish ERH from the other. Furthermore, parenchymal morphology in the central cylinder was also a good criterion to differentiate between EIH and EEH, since EIH demonstrated parenchymal cells that were shaped like a rounded-triangle, whereas EEH parenchymal cells were chrysanthemum-shaped. Conclusions : The identification-keys established in this study would facilitate the accurate identification of microscopic features of the four varieties of 'Ma-Hwang'.

• International journal of advanced smart convergence
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• 제11권3호
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• pp.187-196
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• 2022

In this paper, we propose an example of designing and constructing a roof-type solar power plant structure equipped with a Pseudo-BIPV (Building-Integrated Photovoltaic) shape suitable for use as a roof of a small warehouse with a sandwich-type panel structure. As the characteristics of the roof-type solar power generation facility to be installed in the small warehouse proposed in this study, the shape of the roof is not a general A type, but a right-angled triangle shape with the slope is designed to face south. We chose a structure in which an inverter for one power plant and a control facility are linked by grouping several roofs of buildings. In addition, the height of the roof structure is less than 20 cm from the floor, and it has a shape similar to that of the BIPV, so it is building-friendly because it is almost in close contact with the roof. At the same time, the roof creates a reflective light source due to the white color. By linking this roof with a double-sided solar panel, we designed it to obtain both the advantage of the roof-friendliness and the advantage of efficiency improvement for the electric power generation based on the double-sided panel. Compared to the existing solar power generation facilities using A-shaped cross-sectional modules, the power generation efficiency of roofs in this case is increased by more than 11%, which we can confirm, through the comparison analysis of monitoring data between power plants in the same area. Therefore, if the roof-type solar structure suitable for the small warehouse we have presented in this paper is used, the facilities of electric power generation is eco-friendly. Further it is easier to obtain facility certification compared to the BIPV, and improved capacity of the power generation can be secured at low material cost. It is believed that the roof-type solar power generation facility we proposed can be usefully used for warehouse or factory-based smart housing. Sensor devices for monitoring, CCTV monitoring, or safety and environment management, operating in connection with the solar power generation facilities, are linked with the Internet of Things (IoT) solution, so they can be monitored and controlled remotely.

• 대한수의학회지
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• 제28권1호
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• pp.1-16
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• 1988

The anatomical structure of pelvic limb, of thirty-one adult Korean native goats (Body weight: 14~17kg) was observed after skeletal preparation, and the osteometry was performed in each bone. The results were as follows: 1. The pelvic limb of the Korean native goat was composed of the hip bone, femur, patella, tibia, fibula, tarsal bones, metatarsal bone, phalanges and sesamoid bones. 2. The hip bone consisted of the ilium, ischium and pubis which fused each other, The gluteal surface of the ilium was directed dorsolaterally. The tuber sacrale and tuber coxae were formed at the dorsal apex and ventrolateral part of the iliac wing, respectively. The lesser ischiatic notch was deeper than the greater one. The ischiatic tubercles were triangular form and consisted of the dorsal, lateral and caudal ischiatic tubercles. The left and right hip bone indexes were 67.08, 66.20, the acetabular indexes were 93.78 and 92.10 and the obturator foramen. indexes were 53.84 and 54.77, respectively. 3. In femur, both of the greater and lesser trochanter were well developed but the third trochanter was not observed. The left and right femur indexes were 26.55 and 26.14, head indexes were 81.66 and 81.49 and the trochlear-epicondyle indexes were 42.47 and 41.63, respectively. 4. The patella was observed as an isosceles triangle with base lying proximal and the cranial surface was more convex. 5. The tibial shaft was sigmoid form and the popliteal notch was deep. There was a large nutrient foramen at the cranial aspect of the cranial intercondylar area. The tibial indexes were 22.09 in left and 21.10 in right. 6. The proximal extremity of the fibula was fused with the lateral condyle of the tibia but the distal one was observed independently as the malleolar bone. 7. The tarsal bones were five in number; the talus, calcaneus, centroquartal tarsal bone, first tarsal bone, and second-third tarsal bone. 8. The metatarsal bone was composed of a large metatarsal bone. resulted from the fusion of the third and fourth metatarsal bones, The structure of metatarsal bone was similar to the metacarpal bone but longer about 7mm. 9. The phalanges and sesamoid bones were similar to these of the thoratic limb. 10. The ratios of the lengths among the hip bone, femur, tibia and metafarsal bone were 1.71 : 1.54 : 1.73 : 1.00 in left and 1.68 : 1.53 : 1.72 : 1.00 in right, respectively.

• 한국실내디자인학회논문집
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• 제19권6호
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• pp.47-58
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• 2010

Frank Lloyd Wright(1867-1959) was regarded as the pioneer of the modern architecture in the beginning and transition period of 20th century. His works have the pure shape form which have the deep relationship with the organic architecture. Wright told himself that the Froebel System had an influence on his works a lot. This study have researched about the three dimensional application of the Froebel System in his works with assembling and disassembling. Also the two dimensional application in the diagonal and circular plans are the one of the subjects here. The following conclusions are reached. First, The similar of the Wright's works and the Froebel System was the application of the similar principles rather than the copy of the method, which are the accent of the center, the composition of the part and whole, the understanding of the composition principle through the unit system and the unfolding of the crystal by rotation. Even thought the Wright's works have the triangle, square, hexagonal shape, the way of the expansion from the centered space was same. Also the space formed by the division of the center space, unfolds making the part and whole by overlap and continuation. The 2nd Froebel make space decided by the Net and Crystal Lattices which have the crystal characteristics by the rotation. The new geometric architecture, pinwheel, was created by this method. The application of the Froebel in the Wright's works have the several sets which are the 3th, 4th, 5th, 6th Froebels, 2nd, 7th Froebels and the 3th, 5th, 9th Froebels. The geometrical analysis of the square shape and the diagonal shape of the Wright's works was possible. The unfolding of the centered space can be found in the Guggenheim Museum using the analysis of the circular geometric of the 9th Froebel. The above study proves that the Froebel was not a mere tool for the basic shape training but also the main body of Wright's works which consists of the organic idea and philosophy of the space.

• Restorative Dentistry and Endodontics
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• 제18권2호
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• pp.395-411
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• 1993

The purpose of this study was to examine the clear concept of the designs for cavity preparations. Among the several parameters in cavity designs, profound understanding of isthmus width factor would facilitate selection of the appropriate cavity preparation for a specific clinical situation. In this study, the cavities were prepared on maxillary first premolar and filled with gold inaly. A two - dimensional model was composed of 1037 - node triangle elements. In this model, isthmus was varied in width at 1/4, 1/3 and 1/2 of intercuspal width and material properties were given for four element groups, i.e., enamel, dentin, pulp and gold. The 500N occlusal load varied in direction and it was examined using three types of load : concentrated load, divided load and distributed load. The models were also examined with empty cavities using the devided load and distributed load. These models were analyzed the displacement and strees distribution by the two - dimensional Finite Element Method. The results were as follows : 1. All experimental models which filled with gold inlay after cavity preparation were similar direction of displacement with control model under same load type. But in the models with empty cavities, as isthmus width was wider, the degree of displacement was increased at same load type. 2. Among the experimental models which were filled with gold inaly after cavity preparation, the model II showed the least stress concentration under concentrated load and divided load. But in the models with empty cavities, the model III showed the largest stress concentration and tooth fracture is expected regardless isthmus width. 3. All experimental models showed similar displacement pattern beneath restorative material under a concentrated load. In the models with empty cavities, a divided load resulted in a lingual displacement of the lingual cusp, but a distributed load resulted in a buccal displacement of the lingual cusp. In regard to the above results, the restored models were stronger than empty models in respect to the bending moment and tensile stress. The empty models are expected to fracture regardless isthmus width. The safest isthmus width was 1/3 of intercuspal distance, which showed the least stress concentration in respect to the effect of stress distribution.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2009년도 춘계학술대회 논문집
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• pp.111-112
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• 2009

Diamond-like carbon (DLC) is a convenient term to indicate the compositions of the various forms of amorphous carbon (a-C), tetrahedral amorphous carbon (ta-C), hydrogenated amorphous carbon and tetrahedral amorphous carbon (a-C:H and ta-C:H). The a-C film with disordered graphitic ordering, such as soot, chars, glassy carbon, and evaporated a-C, is shown in the lower left hand corner. If the fraction of sp3 bonding reaches a high degree, such an a-C is denoted as tetrahedral amorphous carbon (ta-C), in order to distinguish it from sp2 a-C [2]. Two hydrocarbon polymers, that is, polyethylene (CH2)n and polyacetylene (CH)n, define the limits of the triangle in the right hand corner beyond which interconnecting C-C networks do not form, and only strait-chain molecules are formed. The DLC films, i.e. a-C, ta-C, a-C:H and ta-C:H, have some extreme properties similar to diamond, such as hardness, elastic modulus and chemical inertness. These films are great advantages for many applications. One of the most important applications of the carbon-based films is the coating for magnetic hard disk recording. The second successful application is wear protective and antireflective films for IR windows. The third application is wear protection of bearings and sliding friction parts. The fourth is precision gages for the automotive industry. Recently, exciting ongoing study [1] tries to deposit a carbon-based protective film on engine parts (e.g. engine cylinders and pistons) taking into account not only low friction and wear, but also self lubricating properties. Reduction of the oil consumption is expected. Currently, for an additional application field, the carbon-based films are extensively studied as excellent candidates for biocompatible films on biomedical implants. The carbon-based films consist of carbon, hydrogen and nitrogen, which are biologically harmless as well as the main elements of human body. Some in vitro and limited in vivo studies on the biological effects of carbon-based films have been studied [$2{\sim}5$].The carbon-based films have great potentials in many fields. However, a few technological issues for carbon-based film are still needed to be studied to improve the applicability. Aisenberg and Chabot [3] firstly prepared an amorphous carbon film on substrates remained at room temperature using a beam of carbon ions produced using argon plasma. Spencer et al. [4] had subsequently developed this field. Many deposition techniques for DLC films have been developed to increase the fraction of sp3 bonding in the films. The a-C films have been prepared by a variety of deposition methods such as ion plating, DC or RF sputtering, RF or DC plasma enhanced chemical vapor deposition (PECVD), electron cyclotron resonance chemical vapor deposition (ECR-CVD), ion implantation, ablation, pulsed laser deposition and cathodic arc deposition, from a variety of carbon target or gaseous sources materials [5]. Sputtering is the most common deposition method for a-C film. Deposited films by these plasma methods, such as plasma enhanced chemical vapor deposition (PECVD) [6], are ranged into the interior of the triangle. Application fields of DLC films investigated from papers. Many papers purposed to apply for tribology due to the carbon-based films of low friction and wear resistance. Figure 1 shows the percentage of DLC research interest for application field. The biggest portion is tribology field. It is occupied 57%. Second, biomedical field hold 14%. Nowadays, biomedical field is took notice in many countries and significantly increased the research papers. DLC films actually applied to many industries in 2005 as shown figure 2. The most applied fields are mold and machinery industries. It took over 50%. The automobile industry is more and more increase application parts. In the near future, automobile industry is expected a big market for DLC coating. Figure 1 Research interests of carbon-based filmsFigure 2 Demand ratio of DLC coating for industry in 2005. In this presentation, I will introduce a trend of carbon-based coating research and applications.

• 방송공학회논문지
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• 제25권3호
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• pp.325-337
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• 2020

VVC(Versatile Video Coding)는 ISO/IEC/ITU-T의 JVET(Joint Video Experts Team)에서 표준화 중인 새로운 비디오 부호화 표준으로 스크린 콘텐츠 부호화 툴을 포함한 다양한 기술을 채택하고 있다. 스크린 콘텐츠는 문자 영역과 같이 사선 방향 에지가 자주 발생하는 특징을 가지며, 이런 특징을 갖는 영상에 삼각형 형태의 분할 부호화를 적용하면 압축 효율이 증가할 수 있다. 본 논문에서는 스크린 콘텐츠를 위한 VVC 기반 화면내 삼각형 분할 예측 방법을 제안한다. 기존 VVC의 화면간 예측 부호화에서 삼각형 분할 예측을 지원하는 Triangular Prediction Mode 방법과 유사하게, 제안 방법은 화면내 예측 부호화에서 수직과 수평 방향 예측 모드와 주변 복원 참조 라인을 이용하여 두 개의 사각형 예측 블록을 생성하고 삼각형 모양의 마스크로 두 예측 블록을 가중합하여 최종 예측 신호를 만든다. 제안 방법의 실험 결과는 All Intra 스크린 콘텐츠 영상 실험에서 YUV 각각 평균 1.86%, 1.49%, 1.55% 부호화 성능향상을 보이고, 자연 영상 실험 조건에서는 부호화 효율에 미미한 손실을 보였다. 결론적으로, 화면내 예측 부호화 모드에 제안 방법을 적용하여 압축 성능을 향상할 수 있었다.