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.

산지별 홍화씨의 화학적 성분 특성

이영철,안채경,Lee, Young Chul,Ahn, Chae Kyung 한국식품영양학회 2019 韓國食品營養學會誌 Vol.32 No.5

This study was carried out to investigate the chemical properties of safflower seeds cultivated at some areas in Korea. Safflower was used as one of the functional foods and medicinal plants for many centuries. Porximate compositions of safflower seeds were moisture, 4.8~8.1%, crude protein 16.5~19.5%, crude ash 2.7~3.3%, curde fiber 38.5~43.4%, and crude fat 16.6~24.4%, respectively. Glutamic acid, aspartic acid and arginine were the major amino acids and their contents were 2,587.4~3,143.5 mg%, 1,315.8~1,654.8 mg%, and 1,171.9~1,484.2 mg%. K, P, Ca, and Mg were major minerals and their contents were 611.6~886.3 mg%, 501.5~596.7 mg%, 208.5~641.2 mg%, and 530.6~639.5 mg%, respectively. The free sugars that were identified include raffinose, sucrose, glucose, fructose. ${\alpha}$-tocopherol content was 0.14~3.82 mg%. Contents of vitamin C was 0.43~3.39 mg%. The safflower seeds fatty acids were palmitic acid, stearic acid, oleic acid, linoleic acid and linoleic acid. The major fatty acid was linoleic acid it's content was 74.8~82.9%.

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

밀리미터파 SiP 응용을 위한 기생 공진 모드 억제

이영철,Lee Young-Chul 한국전자파학회 2006 한국전자파학회논문지 Vol.17 No.9

In this paper, parasitic resonance modes generated in a conductor backed coplanar wave guide(CBCPW) and stripline band pass filter(BPF) and the oscillation phenomena of a 40 GHz power amplifier module(PAM) are analyzed and several methods to suppress them are presented for low-temperature co-fired ceramic(LTCC) based millimeter-wave RF System-in-Package(SiP) applications. Parasitic rectangular wave guide(RWG) modes of the CBCPW structure are completely suppressed in the operation frequency band by decreasing the distance between its vias and by increasing the mode frequency. In the stripline structure, RWG resonance modes are clearly eliminated by removing some vias facing each other and by placing them diagonally. In the case of the 40 GHz PAM, in order to reduce a cross talk due to radiation that is generated from interconnection discontinuities, high isolation structures such as embedded DC bas lines and CPW signal lines are used and then the oscillated PAM is improved. 본 논문에서는 저온 소성 세라믹(Low-Temperature Co-fired Ceramic: LTCC)에 기초한 밀리미터파 RF SiP(System-in-Package) 모듈 응용을 위하여, CBCPW(Conductor Backed CPW) 전송선과 스트립 라인 대역 통과필터(BPF)에서 기생적으로 발생하는 공진 모드들과 40 GHz 전력 증폭기 모듈의 발진 현상을 분석하고 이를 제거하기 위한 방법들을 제안하였다. CBCPW 구조에서의 기생 구형 도파관(RWG) 모드는 비아의 간격을 줄여 공진 주파수를 높게 하여 동작 주파수 내에서 완전히 억제하였다. 스트립 라인 구조에서는 마주 보는 비아 중한 쪽을 제거하여 대각선으로 비아를 배치함으로써 완전히 제거하였다. CBCPW의 마이크로스트립 패치 공진기 모드들을 제거하기 위하여, 갭을 통한 커플링을 감소시키기 위해 갭에 인접하게 비아를 배치하였다. 그 결과 기생 공진 모드들이 완전히 제거되었다. 40 GHz 대역의 능동 증폭기 모듈의 경우, 상호 연결(interconnection)불연속 효과로 발생한 방사에 의한 인한 누설(cross talk)을 억제하기 위해, LTCC 기판 내부에 내장된 DC 전원 배선과 CPW 전송선의 고 격리 구조를 사용하여 발진 현상을 개선하였다.

해외 학술활동: 미국 자연식품 박람회

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

가변형 박막 유전체에 전극을 임베디드 시킨 고가 변형 커패시터

이영철,홍영표,고경현,Lee Young-Chul,Hong Young-Pyo,Ko Kyung-Hyun 한국전자파학회 2006 한국전자파학회논문지 Vol.17 No.9

본 논문에서는 가변형 $Bi_2O_3-ZnO-Nb_2O_5(BZN)$ Pyrochlore 박막을 이용한 고가변형 inter-digital capacitor를 제안하였다. 가장자리 전계 효과를 이용한 가변성의 향상과 DC 전압의 감소를 위해 inter-digital capacitor의 전극이 박막 내부에 삽입되었다. 2.5D simulator를 이용한 설계 결과, 제 안된 구조의 inter-digital capacitor(IDC)가 일반적인 구조의 IDC에 비해 가변성이 10 % 향상되었다. 제안된 IDC는 설계 결과를 바탕으로 실리콘 기판 위에 BZN 박막을 이용하여 제작되었다. BZN 박막은 reactive RF magnetron sputtering 방법을 이용하여 증착되었다. 제작된 inter-digital capacitor는 5.8 GHz와 18 V의 DC 인가 전압에서 최대 가변율이 50 %였다. In this paper, a novel tunable inter-digital capacitor using dielectric tunable $Bi_2O_3-ZnO-Nb_2O_5(BZN)$ pyrochlore thin films is proposed. In order to improve the tunability and reduce DC bias voltage using the fringing electric field, the electrodes of the inter-digital capacitor are embedded in the thin film. Designed results using a 2.5 D simulator show that the tunability of the proposed inter-digital capacitor improves by 10 %, compared to the conventional inter-digital capacitor. The proposed IDC, which is based on the simulation results, was fabricated, using the BZN thin film deposited by a reactive RF magnetron sputtering on the on the silicon substrate. The fabricated inter-digital capacitor shows the maximum tunability of 50 % at 5.8 GHz and 18 V DC applied.

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.