대형주강품에 대한 CAE 시스템 개발 연구

이영철,이두호,김종기,소찬영,최정길,홍준표 ( Young Chul Lee,Doo Ho Lee,Jong Ki Kim,Chan Young So,Jeong Kil Choi,Chun Pyo Hong ) 한국주조공학회 1997 한국주조공학회지 Vol.17 No.5

N/A An integrated computer program consisting of a pre-processor, main solver, and post-processor was developed for the design of large steel castings. The pre-processor, based on the AutoCAD, enables the user to produce approval drawings, casting design drawings and mesh diagrams in sequence using a personal computer. In the main solver, two numerical models were employed; one models the fluid flow during mold filling, and the other models the heat transfer and solidification. The post-processor can be used to present simulation results such as flow pattern, mold filling sequences, solidification times, temperature gradients and location of shrinkage defects by color graphics. In order to validate the applicability of the present integrated program, a series of experiments on simple-shaped steel castings were carried out. After the validation of the present model, it was applied to the casting design of the large steel anchor of an SC42 alloy. Various solidification parameters such as a temperature distribution and a solidification time in the casting and the mold were compared with those obtained experimentally. Simulated results predicting shrinkage defects were in good agreement with those obtained experimentally. It was found that the present method can be successfully applied to the quantitative casting design for complex-shaped large steel castings. (Received June 4, 1997)

屠殺方法 및 死後時間經過에 따르는 조직비반세포의 出現狀況에 關한 實驗的硏究

李永哲(Young Chul Lee) 대한외과학회 1964 Annals of Surgical Treatment and Research(ASRT) Vol.6 No.5

위암의 연령에 따른 차이

김영재(Young Jae Kim),이영철(Young Chul Rhee),이만길(man Kill Lee),차호(Ho Cha),정영채(Young Chae Jung) 대한소화기학회 1987 대한소화기학회지 Vol.19 No.1

N/A Comparative analytic review on clinical, endoscopic and histopathological findings was done in 13 cases of young age (under 29), 446 cases of mid age (30~69) and 39 cases of old age (above 70) stomach cancer who were visited Department of Internal Medicine of Masan Koryo General Hospital from March 1981 to July 1985. The following results were obtained: The peak of age incidence was the 5th decade amounting to 36.8%. The ratio between male and female was 2.6:1. The main chief complaint of each group was epigastric pain and it was followed by epigastric fullness. The most patient had the duration of symptom from 3 months to 6 months. For old-age group, mid-age group, major site of lesion in the antrum, meanwhile body for young-age group. The most frequent type of gastric cancer was type III in each group by Borrmanns classification. For each group, adenocarcinoma was major cases in the view of histopathological findings, and incidence of well differentiated type adenocarcinoma were lower in young-age group than others.

Biomass 유래 퓨란계 단량체를 이용한 폴리에스터의 중합 및 특성 연구

정용석(Yong Seong Chung),이영철(Young Chul Lee),서강진(Kang Jin Seo),김명준(Myeong Jun Kim),정지혜(Ji Hea Jeong),노시태(Si Tae Noh) 한국고분자학회 2011 폴리머 Vol.35 No.6

바이오매스에서 유래된 2,5-dihydroxymethylfuran(DHMF)을 KMnO4 산화반응으로 furan-2,5- dicarboxylic acid(FDCA)를 합성하였다. 합성한 FDCA와 다이올류를 에스테르화 반응과 축중합 반응을 진행시 켜 폴리에스터를 중합하였다. 폴리에스터는 NMR을 통해 조성을 분석하였고 DSC와 TGA를 통해 열적특성을 분 석하였다. 합성된 폴리에스터의 고유점도는 0.78∼1.2 dL/g으로 상용화된 poly(ethylene terephthalate)(PET) 와 비슷하였다. 다이올의 길이가 증가할수록 Young`s modulus와 strength는 낮아지고 elongation-to-break는 높아지는 경향을 확인하였다. 합성한 poly(ethylene furandicarboxylate)(PEF)의 Young`s modulus는 3551 MPa, strength는 103 MPa로 상용화된 PET와 비슷하였다. Furan-2,5-dicarboxylic acid (FDCA) was synthesized by KMnO4 oxidation of 2,5-dihydroxymethylfuran( DHMF) derived from biomass. Polyesters were synthesized by esterification and polycondensation of FDCA with various diols(ethane-1,2-diol, propane-1,3-diol, butane-1,4-diol, hexane- 1,6-diol, decane-1,10-diol). The composition of polyesters was characterized by using 1H NMR. Thermal properties of the polyesters were characterized by DSC and TGA. Intrinsic viscosities(IV) of the polyesters were measured to be 0.78∼1.2 dL/g comparable with IV of commercial poly(ethylene terephthalate)(PET). As the chain lengths of diols increased, Young`s modulus and strength decreased and elongation-to-break generally increased. Young`s modulus and strength of the polyesters were measured to be 3551 MPa and 103 MPa, respectively, comparable with commercial PET.

개선된 조건 합 가산기를 이용한 $54{\times}54$-bit 곱셈기의 설계

이영철,송민규,Lee, Young-Chul,Song, Min-Kyu 대한전자공학회 2000 電子工學會論文誌-SD (Semiconductor and devices) Vol.37 No.1

개선된 조건 합 가산기를 이용한 저전력 고속 $54{\times}54$-bit 곱셈기를 설계했다. 지연시간을 감소시키기 위해, Booth's Encoder 없이 높은 압축 율을 갖는 압축기들과 Carry 발생블록을 분리시킨 108-bit 조건 합 가산기를 제안하였다. 또한, 지연시간과 전력소모를 최적화하기 위해 패스 트랜지스터로직을 사용한 설계기법을 제안하였다. 제안된 곱셈기는 기존 곱셈기구조에 비해 약 12%의 지연시간과 5%의 전력소모가 감소하였으며, 0.65${\mu}m$ CMOS(Single-poly, triple-metal)공정을 사용하여 $6.60{\times}6.69mm^2$의 칩 크기와 공급전압 3.3V에서 13.5ns의 지연시간을 갖는다. In this paper, a $54{\times}54$-bit multiplier based on a improved conditional sum adder is proposed. To reduce the multiplication time, high compression-rate compressors without Booth's Encoding, and a 108-bit conditional sum adder with separated carry generation block, are developed. Furthermore, a design technique based on pass-transistor logic is utilized for optimize the multiplication time and the power consumption by about 5% compared to that of conventional one. With $0.65{\mu}m$, single-poly, triple-metal CMOS process, its chip size is $6.60{\times}6.69\;mm^2$ and the multiplication time is 135.ns at a 3.3V power supply.

반복 금형주조용 자동 금형냉각장치 개발 및 적용 1 : 용탕충진거동 및 응고해석

이영철,이상목,최정길,홍준표 ( Young Chul Lee,Sang Mok Lee,Jeong Kil Choi,Chun Pyo Hong ) 한국주조공학회 1998 한국주조공학회지 Vol.18 No.2

N/A A three dimensional simulation program based on the SOLA-VOF technique was developed for the modeling of mold filling and solidification sequences of the AC4B alloy in the cyclic permanent mold casting process. The geometries and mesh diagrams of the casting and the mold were automatically generated using a pre-processor based on the commercial Auto-CAD system. The solidification time of the casting and the temperature variation of the mold with cyclic casting were evaluated using the present scheme. The effects of the local water cooling of the metal mold on the cyclic casting process were also examined in order to control the temperature variation in the mold and to improve the soundness of the castings. The minimization of the casting cycle time was also confirmed by the present program for an improved productivity. It can be concluded that the present program can be used for obtaining the optimum casting parameters and the local cooling condition for obtaining sound castings without shrinkage defects in the cyclic mold casting process. (Received March 2, 1998)

ACF를 이용한 3차원 패키지의 제조 공정에 대한 연구

이영철,김종웅,김광석,유정희,정승부,Lee, Young-Chul,Kim, Jong-Woong,Kim, Kwang-Seok,Yu, Chong-Hee,Jung, Seung-Boo 대한용접접합학회 2009 대한용접·접합학회지 Vol.27 No.3

해외 학술활동: 미국 자연식품 박람회

이영철,Lee, Young-Chul 한국식품연구원 2010 食品技術 Vol.23 No.2

정어리유의 용매분별과 분별유의 이용

이영철,김영붕,김기성 ( Young Chul Lee,Young Boong Kim,Kee Sung Kim ) 한국유화학회 1989 한국응용과학기술학회지 Vol.6 No.2

In order to fractionate sardine oil by different solvents for an effective use of fish oil being subjected to the limit of use, an attempt was to investigate the proper solvents, ratios and fractionation time. The results of the study were as follows: 1. The proper solvent of fractionation using ethanol, isopropyl alcohol, acetone, and hexane was ethanol, and its optimum ratio was 2:1 (ethanol: oil, v/w). The proper time of ethanol fractionation by the ratio (2:1) was 4hr at 10℃, 6hr at 5℃, 8hr at 0℃ and 8hr at -5℃, respectively. 2. In the fractionation by stages using the ratio (2:1) at each temperature, the yield of stearine was 8% at 10℃ (Fraction Ⅰ), 32% at 5℃ (Fraction Ⅱ), 7% at 0℃ (Fraction Ⅲ) and 10% at 0℃ (Fraction Ⅳ), respectively. When ethanol fractionation was undertaken at 5℃ by stages, the yield of stearine (Fraction Ⅱ) was high. 3. lodine value of Fraction Ⅱ was 96.8. This result indicated that the hydrogenation process would be simpliied by fractionation 4. The percentage of the decrease of polyenoic acids from original sardine oil to Fraction Ⅱ oil was from 30.5% to 13.5%. The major fatty acids of Fraction Ⅱ were palmitic and oleic acids and these fatty acids were about 52% of total fatty acids. Therefore, Fraction Ⅱ, which remained liquid oil at room temperature because solid fat content was 6.9% at 20℃, would be used as frying oil.

초소형 60 GHz LTCC 전력 증폭기 모듈

이영철,Lee, Young-Chul 한국전자파학회 2006 한국전자파학회논문지 Vol.17 No.11

본 논문에서는 저온 소성 세라믹(LTCC)에 기초한 SiP 기술을 이용하여 60 GHz 무선 통신을 위한 송신기용 초소형 전력 증폭기 LTCC모듈을 설계 및 제작하여 그 특성을 측정하였다. 60 GHz대역에서 LTCC 다층 기판과 전력 증폭기 MMIC의 상호 연결 손실을 줄이기 위해 와이어 본드와 기판 사이의 천이를 최적화하였고, MMIC 집적을 위한 고 격리 구조를 제안하였다. 와이어 본드 천이의 경우, 와이어의 인덕턴스를 감소시키기 위해 매칭 회로의 설계와 와이어 상호간의 간격을 최적화하였다. 또한 상호 연결 불연속 효과로 인한 전계의 방사를 억제하기 위해 코프라나 와이어 본드 구조를 이용하였다. 고 격리 모듈 구조를 위하여, LTCC 기판 내부에 DC 전원 배선을 내장시키고 비아로 그 주위를 차폐를 시켰다. 5층의 LTCC 기판을 사용하여 제작된 전력 증폭기 LTCC모듈의 크기는 $4.6{\times}4.9{\times}0.5mm^3$이고, $60{\sim}65GHz$ 대역에서 이득과 P1dB 출력 전력은 각각 10 dB와 11 dBm이다. In this paper, using low-temperature co-fired ceramic(LTCC) based system-in-package(SiP) technology, a very compact power amplifier LTCC module was designed, fabricated, and then characterized for 60 GHz wireless transmitter applications. In order to reduce the interconnection loss between a LTCC board and power amplifier monolithic microwave integrated circuits(MMIC), bond-wire transitions were optimized and high-isolated module structure was proposed to integrate the power amplifier MMIC into LTCC board. In the case of wire-bonding transition, a matching circuit was designed on the LTCC substrate and interconnection space between wires was optimized in terms of their angle. In addition, the wire-bonding structure of coplanar waveguide type was used to reduce radiation of EM-fields due to interconnection discontinuity. For high-isolated module structure, DC bias lines were fully embedded into the LTCC substrate and shielded with vias. Using 5-layer LTCC dielectrics, the power amplifier LTCC module was fabricated and its size is $4.6{\times}4.9{\times}0.5mm^3$. The fabricated module shows the gain of 10 dB and the output power of 11 dBm at P1dB compression point from 60 to 65 GHz.