• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2010년도 춘계학술발표대회 초록집
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• pp.80-80
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• 2010

전자제품의 소형화, 경량화, 고집적화가 심화됨에 따라 전자제품을 구성하는 회로의 미세화 또한 요구되고 있다. 이러한 요구는 경성회로기판 (rigid printed circuit board, RPCB) 뿐만 아니라 연성회로기판 (flexible printed circuit board, FPCB) 에도 적용되고 있으며 이에 대한 많은 연구 또한 이루어지고 있다. 연성회로기판은 일반적으로 절연층을 이루는 폴리이미드 (polyimide, PI)와 전도층을 이루는 구리로 이루어져 있다. 폴리이미드는 뛰어난 열적 화학적 안정성, 우수한 기계적 특성, 연속공정이 가능한 장점을 가지고 있으나, 고온다습한 환경하에서 높은 흡습성으로 인해 전도층을 이루는 구리와의 접합특성이 저하되는 단점 또한 가지고 있다. 또한 전도층을 이루는 구리는 고온다습한 환경하에서 산화 발생이 용이하기 때문에 접합특성의 감소를 야기할 수 있다. 따라서 본 연구에서는 고온다습한 조건하에서 sputtering and plating 공정을 통해 순수 Cr seed layer를 가지는 연성회로기판의 seed layer의 두께와 시효시간의 변화로 인해 발생하는 접합특성의 변화를 관찰하고 분석하였다. 본 연구에서는 두께 $25{\mu}m$의 일본 Kadena사(社)에서 제작된 폴리이미드 상에 sputtering 공정을 통해 순수 Cr으로 이루어진 각각 두께 100, 200, $300{\AA}$의 seed layer를 형성한 후 전해도금법을 이용, 두께 $8{\mu}m$의 구리 전도층을 형성한 시료를 사용하였다. 제작된 시료는 고온다습한 환경하에서의 접합 특성의 변화를 관찰하기 위하여 $85^{\circ}C$/85%RH 항온항습 조건하에서 각각 24, 72, 120, 168시간 동안 시효처리 한 후, Interconnections Packaging Circuitry (IPC) 규격에 의거하여 접합강도를 측정하였다. 시료의 전도층은 폭 3.2mm 길이 230mm의 패턴을 가지도록, 절연층은 폭 10mm, 길이 230mm으로 구성되었으며 이를 50.8mm/min의 박리 속도로 각 시편당 8회의 $90^{\circ}$ peel test를 실시하였다. 파면의 형상과 화학적 조성을 분석하기 위해 SEM (Scanning electron microscope)과 EDS (Energy-dispersive X-ray spectroscopy)를 사용하였으며, 파면의 조도 측정을 위해 AFM (Atomic force microscope)을 사용하였다. 또한 계면의 화학적 결합상태를 분석하기 위해 XPS (X-ray photoelectron spectroscopy)를 통해 파면을 관찰 분석하였다.

• Tuberculosis and Respiratory Diseases
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• 제49권3호
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• pp.365-371
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• 2000

유전분증은 비정상적인 섬유성 형태의 단백질이 세포 외 조직에 침착하는 질환이고, 원발성 폐유전분증은 매우 드물게 보고되고 있다. 원발성으로 발생한 경우 기관기관지형은 기도폐쇄를 일으킬 경우에 외과적 절제술이나 레이저 치료술로 치료를 해야하고 미만성 폐포격막형인 경우 호흡부전과 객혈 등으로 예후가 나쁘지만, 결절성인 경우에는 대부분 예후가 좋은 편이나, 드물게는 호흡곤란, 중증 객혈, 및 호흡부전을 일으킬 수 있으며 단일 결절일 때는 악성 종양과의 감별 및 치료적 방법으로 수술적 절제가 필요할 수도 있다. 저자들은 타 장기의 침윤이 없이 폐에만 단독으로 침범한 원발성 다발성 결절성 유전분증 1예를 조직검사를 통하여 확진 후 문헌 고찰과 함께 보고하는 바이다.

• KDI Journal of Economic Policy
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• 제13권4호
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• pp.155-177
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• 1991

본고(本稿)에서는 최근 한반도(韓半島) 주변정세(周邊情勢)의 변화(變化)와 북한(北韓)의 개방전망(開放展望) 및 현재 추진중에 있는 남북한(南北韓) 경제교류(經濟交流)의 현황(現況)을 분석한 다음, 앞으로 추진해 나가야 할 남북한(南北韓) 경제협력(經濟協力)의 기본방향(基本方向)과 물자교류(物資交流) 및 합작투자(合作投資)의 추진(推進) 등 실질적(實質的)인 경제교류(經濟交流) 협력방안(協力方案)을 제시하였다. 현재 북한(北韓)이 처해 있는 대내외적(對內外的) 상황(狀況)은 북한(北韓)의 개방(開放)을 불가피하게 하고 있어, 북한(北韓)은 남북한(南北韓) UN 동시가입(同時加入)을 계기로 침체된 북한경제의 회복을 위해 UNDP, UNIDO 등 국제기구(國際機構)를 통한 대서방(對西方) 경제협력(經濟協力)을 적극 추진할 것으로 예상되며, 이는 남북한(南北韓) 경제협력(經濟協力)의 증대(增大)로 연계될 것이다. 그러나 초기단계(初期段階)의 남북한(南北韓) 경제협력(經濟協力)은 분쟁의 요소가 적고 또한 남북한(南北韓) 관계개선(關係改善)의 파급효과(波及效果)가 큰 분야에서부터 시작하는 것이 필요하며, 쌍방의 수용이 가능한 사업부터 순차적으로 추진하여 현행 간접무역형태(間接貿易形態)에서 직접무역형태(直接貿易形態)로 발전시키고, 제3국으로의 공동진출(共同進出), 남북한(南北韓) 경제협력측면(經濟協力側面)에서의 간접(間接) 직접투자(直接投資)에 이르는 단계별(段階別) 접근(接近)이 필요하며, 연쇄효과(linkage effect)의 극대화를 위해 다단계(多段階) 동시추진(同時推進)의 유연성(柔軟性)도 고려되어야 한다. 또한 남북한(南北韓) 경제교류(經濟交流)의 기본목표(基本目標)는 민족경제공동체(民族經濟共同體)를 형성하기 위한 기반을 조성하는 것이므로 점차 활성화(活性化)가 예상되는 남북한(南北韓)의 경제교류(經濟交流) 협력(協力)의 추진(推進)은 교역단계(交易段階), 자본(資本) 기술협력단계(技術協力段階)뿐만 아니라 민족경제공동체(民族經濟共同體) 형성(形成) 이후 남북한(南北韓) 산업구조조정필요성(産業構造調整必要性) 등 전체의 흐름을 염두에 두고 반드시 장기적(長期的)인 시각(視角)에서 일관성(一貫性) 있게 추진되어야 할 것이다.

• Journal of Dental Anesthesia and Pain Medicine
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• 제15권4호
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• pp.207-212
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• 2015

Background: The ideal alternative airway device should be intuitive to use, yielding proficiency after only a few trials. The Clarus Video System (CVS) is a novel optical stylet with a semi-rigid tip; however, the learning curve and associated orodental trauma are poorly understood. Methods: Two novice practitioners with no CVS experience performed 30 intubations each. Each trial was divided into learning (first 10 intubations) and standard phases (remaining 20 intubations). Total time to achieve successful intubation, number of intubation attempts, ease of use, and orodental trauma were recorded. Results: Intubation was successful in all patients. In 51 patients (85%), intubation was accomplished in the first attempt. Nine patients required two or three intubation attempts; six were with the first 10 patients. Learning and standard phases differed significantly in terms of success at first attempt, number of attempts, and intubation time (70% vs. 93%, $1.4 {\pm}0.7$ vs. $1.1{\pm}0.3$, and $71.4{\pm}92.3s$ vs. $24.6{\pm}21.9s$, respectively). The first five patients required longer intubation times than the subsequent five patients ($106.8{\pm}120.3s$ vs. $36.0{\pm}26.8s$); however, the number of attempts was similar. Sequential subgroups of five patients in the standard phase did not differ in the number of attempts or intubation time. Dental trauma, lip laceration, or mucosal bleeding were absent. Conclusions: Ten intubations are sufficient to learn CVS utilization properly without causing any orodental trauma. A relatively small number of experiences are required in the learning curve compared with other devices.

• 대한전자공학회논문지SD
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• 제45권12호
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• pp.1-7
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• 2008

Magnetic Tunnel Junction (MTJ)는 비휘발성 소자로서 그간 기억소자분야에 국한되어왔으나, 최근 다양한 연구들에 의하여 자기논리 (magneto-logic) 회로에 사용되면서 기존 트랜지스터 기반의 논리연산자를 대체할 수 있는 가능성을 보이고 있으며, 논리회로까지 확장 적용되어 스핀전자공학 분야의 새로운 장을 열 것으로 기대되어지고 있다. 자체 저장 능력을 갖는 MTJ 소자로 구현된 자기논리 회로는 전원이 꺼져도 정보가 그대로 유지되고, 또한, 불 (Boolean) 연산 수행 시 단순한 입력변화만으로 다양한 논리 연산자 구현이 가능한 구조적인 유연성을 보이므로, 물리적으로 완성된 회로 내에서 얼마든지 재구성이 가능한 자기논리 회로를 구현할 수 있다. 본 논문에서는 단순한 조합논리나 순차논리 회로의 동작을 넘어서, 임의의 3비트 논리회로 동작을 모두 수행할 수 있는 자기논리 회로를 제안한다. 이를 위해 3비트 논리회로 중에서 최대의 복잡성을 갖는 논리회로를 MTJ 소자를 사용하여 설계하였고, 그 동작을 이전 논문에서 제안된 바 있는 macro-model을 보완 적용하여 검증하였다. 제안된 회로는 3비트로 구현할 수 있는 가장 복잡한 논리회로의 동작을 수행할 뿐만 아니라, 전류구동회로의 게이트 신호들을 변화시킴으로써 임의의 3비트 논리 회로의 동작을 모두 수행하는 것이 가능하다.

• Steel and Composite Structures
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• 제22권5호
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• pp.1001-1018
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• 2016

The purpose of this paper is to compare the structural responses obtained from the stochastic analysis of a suspension bridge subjected to uniform and partially correlated seismic ground motions, using different spatial correlation functions commonly used in the earthquake engineering. The spatial correlation function employed in this study consists of a term that characterizes the loss of coherency. To account for the spatial variability of ground motions, the widely used four loss of coherency models in the literature has been taken into account in this study. Because each of these models has its own characteristics, it is intended to determine the sensitivity of a suspension bridge due to these losses of coherency models which represent the spatial variability of ground motions. Bosporus Suspension Bridge connects Europe to Asia in Istanbul is selected as a numerical example. The bridge has steel towers that are flexible, inclined hangers and a steel box-deck of 1074 m main span, with side spans of 231 and 255 m on the European and Asian sides, respectively. For the ground motion the filtered white noise model is considered and applied in the vertical direction, the intensity parameter of this model is obtained by using the S16E component of Pacoima Dam record of 1971 San Fernando earthquake. An analytically simple model called as filtered white noise ground motion model is chosen to represent the earthquake ground motion. When compared with the uniform ground motion case, the results obtained from the spatial variability models with partial correlation outline the necessity to include the spatial variability of ground motions in the stochastic dynamic analysis of suspension bridges. It is observed that while the largest response values are obtained for the model proposed by Harichandran and Vanmarcke, the model proposed by Uscinski produces the smallest responses among the considered partially correlated ground motion models. The response values obtained from the uniform ground motion case are usually smaller than those of the responses obtained from the partially correlated ground motion cases. While the response values at the flexible parts of the bridge are totally dominated by the dynamic component, the pseudo-static component also has significant contributions for the response values at the rigid parts of the bridge. The results also show the consistency of the spatial variability models, which have different characteristics, considered in this study.

• 대한치과보철학회지
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• 제33권4호
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• pp.780-806
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• 1995

The purpose of this study was to describe the application of 3D finite element analysis to determine resultant stresses on the bone anchored fixed prosthesis, implants and supporting bone of the mandible according to fixture numbers and load conditions. 4 or 6 fixtures and the bone anchored fixed prosthesis were placed in 3D finite element mandibular arch model which represents an actual mandibular skull. A $45^{\circ}$ diagonal load of 10㎏ was labiolingually applied in the center of the prosthesis(P1). A $45^{\circ}$ diagonal load of 20㎏ was buccolingually applied at the location of the 10mm or 20mm cantilever posterior to the most distal implant(P2 or P3). The vertical distribution loads were applied to the superior surfaces of both the right and the left 20mm cantilevers(P4). In order that the boundary conditions of the structure were located to the mandibular ramus and angle, the distal bone plane was to totally fixed to prevent rigid body motion of the entire model. 3D finite element analysis was perfomed for stress distribution and deflection on implants and supporting bone using commercial software(ABAQUS program. for Sun-SPARC Workstation. The results were as follows : 1. In all conditions of load, the hightest tensile stresses were observed at the metal lates of prostheses. 2. The higher tensile stresses were observed at the diagonal loads rather than the vertical loads 3. 6-implants cases were more stable than 4-implants cases for decreasing bending and torque under diagonal load on the anterior of prosthesis. 4. From a biomechanical perspective, high stress developed at the metal plate of cantilever-to-the most distal implant junctions as a consequence of loads applied to the cantilever extension. 5. Under diagonal load on cantilever extension, the 6-implants cases had a tendency to reduce displacement and to increase the reaction force of supporting point due to increasing the bendign stiffness of the prosthesis than 4-implants cases. 6. Under diagonal load on cantilever extension, the case of 10mm long cantilever was more stable than that of 20mm long cnatilever in respect of stress distribution and displacement. 7. When the ends of 10mm or 20mm long cantilever were loaded, the higher tensile stress was observed at the second most distal implant rather than the first most distal implant. 8. The 6-implants cases were more favorable about prevention of screw loosening under repeated loadings because 6-implants cases had smaller deformation and 4-implants cases had larger deformation.

• 복식
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• 제50권3호
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• pp.59-72
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• 2000

Dragon robe was defined as a robe on which the principal design consisted of dragon. Dragon patterns have been used on princess robes during T'and Dynasty. In Sung, Dragon-figured robes seem to have an Imperial prerogative. Yuan took over the use of robes with dragons patterns as a definite institition. Ming tried to reject all Yuan innovations, the dragon robe was retained as an unofficial court costume. The Emperor's semiformal robes which at first had four dragon medallions, later had twelve along with the 12 Symbols(십이장문). As Ch'ing dragon robes were only intended fro semiformal use. The Later Ch'ing robes date from after 1719, when the Ch'ien-lung(건륭) introduced 12 Symbols on Ch'ing robes. The Ch'ien-lung laws were disobeyed, notably the ones that specified the number of claws on the dragons. THe Emperor's dragon robe, lung-p'ao, (용포) was described as bright yellow in color, having four slits and horsefoof cuffs. The basic pattern consisted of nin dragons, in addition it had 12 Symbols. The elaborate textile techniques reached their peak in Ch'ing Dynasty-with its Weaving and Dyeing Office in Peking, and this factories at Hangchow(항주), Soochow(소주), and Naking(남경) -helps to explain why the decay of the Ch'ing bureaucracy hastended the decline of dragon robes. In the Ch'ing Dynasty tow terms were used for dragon robe, depending on the number of claws on the dragons. Those with five-clawed dragons were called lung-p'ao, while those with four-clawed dragons were called mang-p'ao(망포). The Court felt compelled to take corrective meausres. It decreeed that Ninisters of State and other officials, who had been bestowed five-clawed lung dragons, must take out one claw. Finally, the sale of ranks and the attendant privilege of wearing dragon robes gradually increased during the 18 th century, reaching its height in the 19 th century, Finally, after the Taiping Rebellion, when the Imperial Treasury was depleted by the wholesale destruction of revenue-producing lands, the Chinese government came to depend on such sales as an important source of revenue and the practice became even more widespread. The ensuing mass production of dragon robes, and the necessity of conforming to the fairly rigid basic pattern established in 1759, resulted in marked deterioration of workmanship, and a comparative monotony of decoration. The patterns on the dragon robes slight changes continued to be made in the ways of representign them. The li shui (입수) portion at the base of the robe become inreasingly wider throughout the 19th century. The background became cluttered with symbols of good fortune, scattered among the clouds and waves. As a result of all this extraneous decoration, the dragons were so crowded that they had to shrink back into the small size that they had originally occupied in the medallons. Kuang-hsu(광저) was a long one, allowing time for the manufacture of numerous robes. Also, it would seem likely that Occidental museums and collections would have a considerable number of his robes, in view of the widespread looting of his palaces during the Allied occupation of Peking in 1900, and the frequent sales of Late Ch'ing imperial textiles by destitute Manchu courtiers in the '20's.

• 토지주택연구
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• 제2권3호
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• pp.287-297
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• 2011

본 논문은 적층고무형베어링을 갖는 15층 면진 무량판 아파트건물의 내진거동을 진동대실험을 통하여 검증한 결과를 제시하고 있다. 진동대실험은 중국의 CABR에서 1/10규모의 모형실험체를 대상으로 수행되었다. 실험의 진행은 4개의 지진파를 이용하여 X, Y, X+Y방향으로 다양한 크기의 지진동이 입력되었다. 실험결과, 비 면진건물은 중진레벨에서 진동주기가 현저히 감소하고, 비선형적인 거동을 보였으며, 가속도가 건물의 높이에 따라 현저하게 증가하고, 층간변위도 허용한계를 넘는 거동을 보였다. 반면, 면진건물은 중진레벨에서 거의 일정한 진동주기의 탄성적인 거동을 나타내었으며, 지진하중과 층 가속도가 현저하게 감소하는 응답을 나타내었다. 또한 면진층의 변위는 허용범위 내에서 거동하고, 층간변위는 무시할 수 있을 만큼 작은 강체거동을 나타내었다. 결론적으로 면진은 건물에 대한 지진의 영향을 감소시키는데 매우 효과적이며, 층 가속도의 감소를 통하여 사용성을 증가시키고, 건물 내 설비 등을 안전하게 보호할 수 있음이 입증되었다.

• 한국재료학회지
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• 제30권10호
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• pp.566-572
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• 2020

In the recent years, thin film solar cells (TFSCs) have emerged as a viable replacement for crystalline silicon solar cells and offer a variety of choices, particularly in terms of synthesis processes and substrates (rigid or flexible, metal or insulator). Among the thin-film absorber materials, SnS has great potential for the manufacturing of low-cost TFSCs due to its suitable optical and electrical properties, non-toxic nature, and earth abundancy. However, the efficiency of SnS-based solar cells is found to be in the range of 1 ~ 4 % and remains far below those of CdTe-, CIGS-, and CZTSSe-based TFSCs. Aside from the improvement in the physical properties of absorber layer, enormous efforts have been focused on the development of suitable buffer layer for SnS-based solar cells. Herein, we investigate the device performance of SnS-based TFSCs by introducing double buffer layers, in which CdS is applied as first buffer layer and ZnMgO films is employed as second buffer layer. The effect of the composition ratio (Mg/(Mg+Zn)) of RF sputtered ZnMgO films on the device performance is studied. The structural and optical properties of ZnMgO films with various Mg/(Mg+Zn) ratios are also analyzed systemically. The fabricated SnS-based TFSCs with device structure of SLG/Mo/SnS/CdS/ZnMgO/AZO/Al exhibit a highest cell efficiency of 1.84 % along with open-circuit voltage of 0.302 V, short-circuit current density of 13.55 mA cm^-2, and fill factor of 0.45 with an optimum Mg/(Mg + Zn) ratio of 0.02.