SOFC 연결재용 Al이 도핑된 (La_0.8Ca_0.2)(Cr_0.9Co_0.1)O₃(LCCC)계 세라믹스의 합성 및 치밀화 특성

이호영,강보경,이호창,허영우,김정주,김재육,이준형,Lee, Ho-Young,Kang, Bo-Kyung,Lee, Ho-Chang,Heo, Young-Woo,Kim, Jeong-Joo,Kim, Jae-Yuk,Lee, Joon-Hyung 한국전기전자재료학회 2012 전기전자재료학회논문지 Vol.25 No.5

In the $(La_{0.8}Ca_{0.2})(Cr_{0.9}Co_{0.1})O_3$ (LCCC), which has been using as interconnector materials in SOFC, Al ions were substituted for Co because ionic radius of Al is similar to that of Co. Because of the almost identical ionic radius of Al and Co, the substitution was not thought to be affect the tolerance factor of LCCC, and the densification behavior, high temperature electrical conductivity and thermal expansion coefficient were examined as a function of Al concentration. In the cases of the x= 0 and x= 0.02 in $(La_{0.8}Ca_{0.2})(Cr_{0.9}Co_{0.1-x}Al_x)O_3$ (x= 0~0.1), the samples showed the relative densities above ${\geq}95%$ when those were sintered at ${\geq}1,350^{\circ}C$. In the case of the $x{\geq}0.06$ the sintered density deteriorated greatly at lower sintering temperatures. High temperature electrical conductivity of the samples decreased as the content of Al increased. Since the valence state of Al ion is unchangeable, while Cr or Co ions contribute to the electrical conduction by changing those valence states, Al substitution resulted in the decreased electrical conductivity. Al doping of LCCC was an effective way of decreasing the thermal expansion coefficient (TEC).

안구위축 혹은 변색된 실명안에서 Scleral Shell 의안 착용 결과에 대한 임상 연구

이호영,양재욱.Ho Young Lee. M.D.. Jae Wook Yang. M.D.. Ph.D. 대한안과학회 2008 대한안과학회지 Vol.49 No.7

Purpose: To show that scleral shells can be good cosmetic prostheses for phthisis bulbi or discolored blind eyes for which no evisceration or enucleation is indicated. Methods: Twenty patients with phthisis bulbi or discolored blind eyes were enrolled in this study. All patients were using scleral shells. We evaluated any complications induced by the scleral shells and the cosmetic results during the follow-up period. Results: The average central thickness of the scleral shell was 1.84±0.26 mm, and the average volume was 1.52±0.25 ml. The average difference in palpebral fissure width between the fellow eye and the eye with a fitted scleral shell was 0.8±0.62 mm. One patient complained about ocular irritation and difficulty in fitting but was satisfied with the cosmetic appearance. Conclusions: Fitting scleral cover shells over phthisis bulbi or discolored blind eyes without evisceration or enucleation could be a successful remedy for enhancing cosmetic appearance. J Korean Ophthalmol Soc 49(7):1041-1045, 2008

Foraminifera from shell deposits of the Jindo Island

이호영,Lee Ho-Young The Korean Society Of Petroleum Geology 1993 한국석유지질학회지 Vol.1 No.1

진도에 분포되는 패각층의 유공충 군집은 온난환경에서 퇴적되었음을 지시한다. 총 12개의 표품에서 10속 11종의 저서성 유공충이 산출되었다. 이중에서 Cavarotalia annectens가 주요종으로 57에서 90퍼센트를 차지한다. 본역의 패각층은 유공충 군집으로 보아 흘로세 퇴적물이다. Foraminiferal assemblages from shell beds of Jindo Island indicate shallow water accumulation under warm to temperate condition near the mouth of a small estuary. 11 species of benthonic Foraminifera belonging to 10 genus have been extracted from 12 samples. Cavarotalia annectens dominates, accounting for 57 to 90 percent of the total fauna. The foraminiferal assemblages of the shell beds indicates Post-glacial sedimentation.

구리계 리드프레임/EMC 접합체의 파괴거동

이호영,유진,Lee, Ho-Young,Yu, Jin 한국재료학회 2000 한국재료학회지 Vol.10 No.8

구리계 리드페임의 표면에 흑생산화물을 형성시키기 위하여 알칼리 용액에 담궈 산화시킨후 EMC(epoxy molding compound)로 몰딩하였고 기계적 가공을 하여 SDCB(sandwiched double-cantilever beam) 및 SBN(sandwiched Brazil-nut)시편을 만들었다. SDCB와 SBN 시편은 리드프레임/EMC 계면의 접착력을 각각 준 mode I 하중 및 혼합모드 하중 하에서 파괴인성치로 측정하기 위하여 고안되었다. 파괴경로를 밝혀내기 위하여 접착력 츨정 후에 얻어진 파면에 대하여 glancing-angle XRD, SEM, AFM, EDS 및 AES를 이용하여 분석하였다. SDCB 실험 후의 파면은 파괴되는 양상에 따라 세 가지 형태로 나눌 수 있었으며, 각 형태는 리드프레임의 접착전 표면 산화물 형성 상태와 밀접한 관계가 있었다. SBN 실험 후의 파면은 균열에서 가까운 부분과 먼 부분으로 나누어지는 특징을 보였는데, 이는 동적 파괴 효과(dynamic fracture effect)에 기인하는 것이라 생각된다. 또한 위상각에 따라 확실히 다른 파괴 양상을 보였는데, 이는 위상각에 따라 mode II 성분이 변하기 때문으로 생각된다. Cu-based leadframe sheets were oxidized ic a hot alkaline solution to black-oxide layer on the surface and molded with epoxy molding compound(EMC), and finally machined to form sandwiched double-cantilever beam(SDCB) and sandwiched Brazil-nut(SBN)specimers to measure the adhesion strength of leadframe-EMC interface. The SDCB and the SBN specimens were designed to measure the adhesion strength in terms fracture toughness under puasi-mode I and mixed mode loadinf, respectively. After the tests, fracture surfaces were analyzed paths were observed in the SDCB-tested speciments, failure paths varied with crack speed and loading conditions.

백내장수술 환자에게 적용된 모노비전(Monovision)에 대한 임상 연구

이호영,허준,Ho Young Lee,Jun Her,Ph,D 대한안과학회 2008 대한안과학회지 Vol.49 No.9

Purpose: To evaluate the clinical results of monovision treatment applied to cataract patients who planned to undergo phacoemulsification and posterior chamber intraocular lens (PC IOL) implantation. Methods: Phacoemulsificaiton and implantation of a monofocal PC IOL were performed in 40 patients between January 2005 and January 2006. Surgeries were performed on the dominant eye with the postoperative goals of emmetropia and on the nondominant eye with the postoperative goals of mild myopia. Patients' satisfaction, refractive change, and visual acuity were evaluated for at least 3 months after the surgery. Results: The mean postoperative uncorrected near visual acuity (UCNVA) of binocular eyes was 0.56±0.52, which was a statistically significant improvement compared with the mean preoperative UCNVA (P<0.001). The mean postoperative uncorrected far visual acuity(UCFVA) of binocular eyes was 0.70±0.34, which was a statistically significant improvement compared with the mean preoperative UCFVA (P<0.001). In all, 77.5% (31 of 40) of patients were satisfied with the results. Conclusions: Monovision induced by phacoemulsification and implantation of a monofocal PC IOL is suggested to be a good option in patients with presbyopia and cataract. J Korean Ophthalmol Soc 2008;49(9):1437-1442

The Pronunciation of English Consonant Clusters by Koreans

이호영,Lee Ho-Young The Korean Society Of Phonetic Sciences And Speech 2000 말소리 Vol.40 No.-

한국어와 영어는 서로 다른 음소 배열 제약과 음운 규칙을 가지고 있기 때문에 영어 학습자들은 특정 영어 자음군을 정확하게 발음하는 데 어려움을 겪게 된다 따라서 이 논문은 영어 학습자들이 어떤 영어 자음군을 배우기 어려워 하고 왜 이러한 어려움이 생겨나는지 한국어와 영어의 음소 배열 제약과 음운 규칙을 비교해서 밝히는 것을 목적으로 한다.

인장하중하에서의 고분자/거친금속 계면의 파손에 대한 비교연구 II: 접착모델

이호영,김성룡,Lee Ho-Young,Kim Sung-Ryong 한국재료학회 2005 한국재료학회지 Vol.15 No.1

Copper based leadframe sheets were immersed in two kinds of hot alkaline solutions to form brown-oxide or blackoxide layer on the surface. The oxide-coated leadframe sheets were molded with epoxy molding compound (EMC). After post mold curing, the oxide-coated EMC-leadframe joints were machined to form sandwiched double-cantilever beam (SDCB) specimens. The SDCB specimens were used to measure the fracture toughness of the EMC/leadframe interfaces under quasi-Mode I loading conditions. After fracture toughness testing, the fracture surface were analyzed by various equipment to investigate failure path. An adhesion model was suggested to explain the failure path formation. The adhesion model is based on the strengthening mechanism of fiber-reinforced composite. The present paper deals with the introduction of the adhesion model. The explanation of the failure path with the proposed adhesion model was introduced in the companion paper.

인장하중하에서의 고분자/거친금속 계면의 파손에 대한 비교연구 I: 실험결과

이호영,김성룡,Lee Ho-Young,Kim Sung-Ryong 한국재료학회 2005 한국재료학회지 Vol.15 No.1

Copper-based leadframe sheets were immersed in two kinds of hot alkaline solutions to form brown-oxide or black-oxide layer on the surface. The oxide-coated leadframe sheets were molded with epoxy molding compound (EMC). After post mold curing, the oxide-coated EMC-leadframe joints were machined to form sandwiched double-cantilever beam (SDCB) specimens. The SDCB specimens were used to measure the fracture toughness of the EMC/leadframe interfaces under quasi-Mode I loading conditions. Fracture surfaces were analyzed by various equipment to investigate failure path. The present paper deals with the failure path, and the cause of the failure path formation with an adhesion model will be treated in the succeeding paper.

국어 핵억양의 음향음성학적 연구

이호영,Lee Ho-Young 대한음성학회 1999 말소리 Vol.38 No.-

Korean intonation has been investigated mainly from the point of view of impressionistic phonetics and phonology. The purpose of this paper is to investigate Korean intonation especially nuclear tones, from the point of view of experimental phonetics. Since what we hear is not always the always as what we see in fundamental frequency contours, acoustic characteristics of Korean nuclear times are first discussed Based m quantitative data similar nuclear times are compared and the relationship between the nuclear ton and sentence type is investigated The relationship between the nuclear tone and the speaker's attitude is also discussed.

병행객체지향 언어에서 행위 방정식을 이용한 상속 변칙

이호영,이준,Lee, Ho-Young,Lee, Joon 한국정보통신학회 1999 한국정보통신학회논문지 Vol.3 No.3

상속 변칙이 발생하는 기본적인 이유는 병행객체에 대해 동기화 코드가 메소드 코드와 적당하게 분할되지 않을 때, 파생 클래스를 만들어내기 위한 코드의 확장이 슈퍼 클래스에 존재하는 동기화 코드와 메소드 코드를 변경하도록 할 때, 그리고 병행 객체지향 언어에서 상속성과 병행성이 결합할 때 발생한다. 강조할 점은 상속 변칙을 피하는 방법이다. 그래서 본 논문에서는 새로운 모델인 객체 모델을 제안하고 행위 방정식을 사용하여 병행 객체지향 언어에서 나타나는 상속 변칙의 문제를 최소화시키고자 한다. The fundamental reason why inheritance anomaly occurs is that for a concurrent object, when synchronization code is not properly separated from the method code, the extension of code to produce a derived class may force the change of both the synchronization code and the method code in the super class, and inheritance is integrated inheritance in a simple and satisfactory way within a concurrent object-oriented language. The main emphasis on how to avoid or minimize inheritance anomaly. Therefore, in this paper we propose a new model, object model, and will minimizes the problem of inheritance anomaly found in concurrent object-oriented programming languages using Behavior Equation.