• 대한한의학방제학회지
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• 제22권1호
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• pp.65-78
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• 2014

Objectives : The purpose of this study was to investigate the interpretation of the Ondam-tang(Ondam-tang, here-in-after referred to as "ODT") prescription in order to obtain the evidence for clinical applications. Methods : We have analyzed the interpretation on the ODT prescription through translations and comparisons based on classic books about the oriental medical prescriptions. Result : 1. ODT was first mentioned in the Jiyangfang(集驗方) which was quoted in the Waitaimiyao (外臺秘要). After that, in book Sanyinjiyibingzhengfanglun(三因極一病證方論), Chen-yan(陳言) completed and recorded in a book organizing prescriptions of ODT now in frequent use. 2. The Banha(半夏) removes the dam(痰-phlegm) and relieves emesis. The Jinpee(陳皮) encourages strengths, and the Bokryoung composes oneself and produces the water. The Licorice(甘草) relieves people's mind, and the Ginger relieves gastrointestinal problems and relieves emesis. Juk-yeo(竹茹) abate of the fever of the Sangcho(上焦). Jisil(枳實) encourages strength, controlling Samcho(三焦) as releasing the congestion of energy. In these ways, numerous symptoms resulted from the imbalances of the Gallbladder(膽) are treated. 3. Meaning of "on(溫-warm)" in ODT regains the original characteristic of the Gallbladder(膽). 4. Treatment mechanism of ODT is 'cooling the Gallbladder(膽)' and 'remedies Samcho(三焦)' and 'eliminates dam(痰)' and 'cure Kiwool(氣鬱-which is kind of depressions) and Saengyen(生涎-which is kind of phlegm)' and 'removes a mismatch between Gallbladder(膽) and Stomache(胃)'. Conclusion : In this study, we have demonstrated various methodologies. This paper will be useful to the future researchers and clinicians to conduct a study on herbal medicines such as the ODT.

• 한국가스학회지
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• 제3권2호
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• pp.1-10
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• 1999

각종 발전설비 및 LNG 저장탱크 등 대형산업구조물의 구조적 건전성을 확보하기 위해서는 강구조물을 형성하는 강용접부의 파괴인성 평가가 필수적이다. 강용접부는 모재와는 달리 다양한 재질적 불균질성을 가지는 경우가 대부분인데, 이러한 불균질성은 파괴변수 및 인성치에 대하여 역학적, 야금학적으로 많은 영향을 미치게 되므로 파괴인성 시험시에는 불균질 인자들의 영향을 반드시 고려해 주어야 한다. 하지만 국내의 경우는 강용접부의 불균질성에 대한 체계적인 연구가 이루어져 있지 않은 상태이므로, 본 논문에서는 강용접부가 가지는 인성적, 강도적 불균질에 대하여 정리하고 이에 따른 문제점을 리뷰하였다.

• 한국컴퓨터정보학회논문지
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• 제15권10호
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• pp.99-104
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• 2010

본 논문은 PIFA의 방사체와 접지면의 물리적 변화없이 안테나의 결합 계수와 공진 주파수를 조절할 수 있는 이동 통신 단말기용 내장형 안테나를 제안하였다. 제안된 안테나는 하나의 단락점에 추가된 인덕턴스에 따라 급전점과 단락점 사이의결합계수 뿐만 아니라 안테나의 공진 주파수도 조절한다. 제안된방법은 전계의 세기가 약한단락점에 인덕터를 연결하여 안테나의 성능 변화를 최소화 했다. PIFA의 단락점과 접지면 사이에 추가된 인덕터의 값이 0nH ~ 3.3nH로 변할 때 조절 가능한 공진 주파수 범위는 1650MHz ~ 1830MHz (약 180MHz)이고 인덕터의 값이 커질수록 안테나의 결합계수는 커진다. 이를 통하여 이동 통신 단말기의 형태 및 사용자의 환경에 따른 임피던스 및 공진 주파수의 변화를 전기적으로 조절하여 부정합에 의한 손실을 최소화했고 안테나 방사 성분의 어떠한 변형 없이 10%의 크기 감소효과를 얻을 수 있다. 1650MHz ~ 1830MHz의 주파수 영역에서 측정된 PIFA의 이득 감소는 0 ~ 3.3nH의 인덕터 값의 변화에 따라 0.93dB 이내이다.

• 한국세라믹학회지
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• 제42권8호
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• pp.554-560
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• 2005

The engineering ceramic needs the properties of high strength, hardness, corrosion-resistance and heat-resistance in order to withstand thermal shock or applied nonuniform stresses without failure. The densely coated porous ceramics can be used for machine component, electromagnetic component, bio-system component and energy-system component by their high-performances from superior coating properties and light-weight characteristics due to the structure including pore by itself. In this study we controlled the porosity of silica and alumina, $8.2\~25.4\%$ and $23.4\~36.0\%$, respectively, by the control of sintering temperature and starting powder size. We made bilayer structures, consisting of a transparent glass coating layer bonded to a thick substrate of different porous ceramics by a thin layer of epoxy adhesive, facilitated observations of crack initiation and propagation. The elastic modulus mismatch could be controlled using different porous ceramics as the substrate layer. Then we applied 150 N force using WC sphere with a radius of 3.18 mm by Hertzian indentation. As a result, the crack initiation in the coating layer was delayed at lower porosity in the substrate layer, and the damage in the coating layer was relatively smaller at the bilayer structure coated on higher elastic substrate.

• 마이크로전자및패키징학회지
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• 제15권2호
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• pp.29-36
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• 2008

본 연구에서는 MEMS 소자의 직접화 및 소형화에 필수적인 through-wafer via interconnect의 신뢰성 문제를 연구하였다. 이를 위하여 Au-Sn eutectic 접합 기술을 이용하여 밀봉(hermetic) 접합을 한 웨이퍼 레벨 MEMS 패키지 소자를 개발하였으며, 전기도금법을 이용하여 수직 through-hole via 내부를 구리로 충전함으로써 전기적 연결을 시도하였다. 제작된 MEMS 패키지의 크기는 $1mm{\times}1mm{\times}700{\mu}m$이었다. 제작된 MEMS패키지의 신뢰성 수행 결과 비아 홀(via hole)주변의 크랙 발생으로 패키지의 파손이 발생하였다. 구리 through-via의 기계적 신뢰성에 영향을 줄 수 있는 여러 인자들에 대해서 수치적 해석 및 실험적인 연구를 수행하였다. 분석 결과 via hole의 크랙을 발생시킬 수 있는 파괴 인자로서 열팽창 계수의 차이, 비아 홀의 형상, 구리 확산 현상 등이 있었다. 궁극적으로 구리 확산을 방지하고, 전기도금 공정의 접합력을 향상시킬 수 있는 새로운 공정 방식을 적용함으로써 비아 홀 크랙으로 인한 패키지의 파괴를 개선할 수 있었다.

• 대한치과보철학회지
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• 제29권2호
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• pp.67-84
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• 1991

This study was carried out to investiagate the residual stress caused by the mismatch of thermal expansion and the bond failure resistance of alloy-porcelain specimens. The thermal expansions of alloys and porcelains were measured by using a straight push-rod dilatometer. Porcelain glass transition temperatures, thermal expansion coefficients, and thermal compatibility indices were derived from length-versus-temperature curves. Strain gauges were used to experimentally determine the Young's moduli of porcelains, the residual stresses of porcelain surface, and tensile bond strengths of the specimens of simulated porcelain metal crown. The obtained results were as follows: 1. The coefficients of thermal expansion for alloys were the minimum of $13.53\mu/^{\circ}C$ and the maximum of $20.11\mu/^{\circ}C$ in the range of $100\sim600^{\circ}C$ and those for porcelains were the minimum of $7.72\mu/^{\circ}C$ and the maximum of $31.24\mu/^{\circ}C$ in the range of $100\sim500^{\circ}C$. 2. The glass transition temperature of porcelains exhibited the same value without my relation to the healing rate, and the thermal disharmony of porcelain and alloy was more affected by porcelains than by the alloys. 3. The Young's moduli of body porcelains were larger than those of opaque porcelains(P<0.01) 4. It seemed that the residual stresses of porcelain surfaces in the porcelainalloy systems were more affected by porcelains than by alleys. 5. The bond strengths of the procelain-base metal alloy systems were larger than those of the porcelain-precious metal alloy systems. The fracture strengths of porcelain surfaces showed significant difference between porcelains (P<0.05).

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.630-630
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• 2013

Recently, atomically smooth hexagonal boron nitride(h-BN) known as a white graphene has drawn great attention since the discovery of graphene. h-BN is a III-V compound and has a honeycomb structure very similar to graphene with smaller lattice mismatch. Because of strong covalent sp2bonds like graphene, h-BN provides a high thermal conductivity and mechanical strength as well as chemical stability of h-BN superior to graphene. While graphene has a high electrical conductivity, h-BN has a highly dielectric property as an insulator with optical band gap up to 6eV. Similar to the graphene, h-BN can be applied to a variety of field, such as gate dielectric layers/substrate, ultraviolet emitter, transparent membrane, and protective coatings. However, up until recently, obtaining and controlling good quality monolayer h-BN layers have been too difficult and challenging. In this work, we investigate the controlled synthesis of h-BN layers according to the growth condition, time, temperature, and gas partial pressure. h-BN is obtained by using chemical vapor deposition on Cu foil with ammonia borane (BH3NH3) as a source for h-BN. Scanning Transmission Electron Microscopy (STEM, JEOL-JEM-ARM200F) is used for imaging and structural analysis of h-BN layer. Sample's surface morphology is characterized by Field emission scanning electron microscopy (SEM, JEOL JSM-7100F). h-BN is analyzed by Raman spectroscopy (HORIBA, ARAMIS) and its topographic variations by Atomic force microscopy (AFM, Park Systems XE-100).

• 마이크로전자및패키징학회지
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• 제6권2호
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• pp.13-21
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• 1999

Flip chip assembly directly on organic boards offers miniaturization of package size as well as reduction in interconnection distances resulting in a high performance and cost-competitive Packaging method. This paper describes the investigation of alternative low cost flip-chip mounting processes using electroless Ni/Au bump and anisotropic conductive adhesives/films as an interconnection material on organic boards such as FR-4. As bumps for flip chip, electroless Ni/Au plating was performed and characterized in mechanical and metallurgical point of view. Effect of annealing on Ni bump characteristics informed that the formation of crystalline nickel with $Ni_3$P precipitation above $300^{\circ}C$ causes an increase of hardness and an increase of the intrinsic stress resulting in a reliability limitation. As an interconnection material, modified ACFs composed of nickel conductive fillers for electrical conductor and non-conductive inorganic fillers for modification of film properties such as coefficient of thermal expansion(CTE) and tensile strength were formulated for improved electrical and mechanical properties of ACF interconnection. The thermal fatigue life of ACA/F flip chip on organic board limited by the thermal expansion mismatch between the chip and the board could be increased by a modified ACA/F. Three ACF materials with different CTE values were prepared and bonded between Si chip and FR-4 board for the thermal strain measurement using moire interferometry. The thermal strain of ACF interconnection layer induced by temperature excursion of $80^{\circ}C$ was decreased with decreasing CTEs of ACF materials.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.285-285
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• 2013

Recently, hexagonal boron nitride (h-BN), which is III-V compound of boron and nitride by strong covalent sp2 bonds has gained great interests as a 2 dimensional insulating material since it has honeycomb structure with like graphene with very small lattice mismatch (1.7%). Unlike graphene that is semi-metallic, h-BN has large band gap up to 6 eV while providing outstanding properties such as high thermal conductivity, mechanical strength, and good chemical stability. Because of these excellent properties, hBN can potentially be used for variety of applications such as dielectric layer, deep UV optoelectronic device, and protective transparent substrate. Low pressure and atmospheric pressure chemical vapor deposition (LPCVD and APCVD) methods have been investigated to synthesize h-BN by using ammonia borane as a precursor. Ammonia borane decomposes to polyiminoborane (BHNH), hydrogen, and borazine. The produced borazine gas is a key material that is a used for the synthesis of h-BN, therefore controlling the condition of decomposed products from ammonia borane is very important. In this paper, we optimize the decomposition of ammonia borane by investigating temperature, amount of precursor, and other parameters to fabricate high quality monolayer h-BN. Synthesized h-BN is characterized by Raman spectroscopy and its absorbance is measured with UV spectrophotometer. Topological variations of the samples are analyzed by atomic force microscopy. Scanning electron microscopy and Scanning transmission Electron microscopy are used for imaging and analysis of structures and surface morphologies.

• 마이크로전자및패키징학회지
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• 제29권2호
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• pp.1-10
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• 2022

최근 반도체 소자는 모바일 전자제품과 wearable 및 flexible한 소자와 기판의 다양한 활용으로 많은 분야에서 폭넓게 사용되고 있다. 이들 반도체 칩 접합 공정 중 기판과 솔더의 열팽창 계수(CTE)의 차이와 기판 및 부품 전체에 인가되는 과도한 열 영향은 소자의 성능 및 신뢰성에 영향을 주며, 최종적으로 휨(warpage) 현상 및 장기 신뢰성 저하 등을 초래한다. 이러한 문제점을 개선하기 위해 저온에서 공정이 가능한 저융점 솔더에 대한 연구가 활발히 진행되고 있다. Sn-Bi, Sn-In 등 다양한 저융점 솔더 합금 중 Sn-Bi 솔더는 높은 항복 강도, 적절한 기계적 특성 및 저렴한 가격 등의 이점이 있어 유망한 저온 솔더로 각광받고 있다. 그러나 Bi의 높은 취성 특성 등 단점으로 인해 솔더 합금의 개선이 필요하다. 본 review 논문에서는 다양한 미량 원소와 입자를 첨가하여 Sn-Bi 소재의 기계적 특성 개선을 위한 연구 동향을 소개하며 이를 비교 분석하였다.