음향방출 신호를 이용한 SWS 490A 고장력강의 접합성 평가에 대한 실험적 연구

이장규,우창기,윤종희,조진호,조대희,박성완,김봉각,구영덕 한국공작기계학회 2004 한국공작기계학회 추계학술대회논문집 Vol.2004 No.-

The object of this study is to investigate the effect of joinability by using acoustic emission (AE) signals and doing a pattern recognition for weld heat affected zone (HAZ) in tensile testing. This study was carried out an SWS 490A high tension steel for electric shielded metal arc welding (SMAW), CO₂ gas arc welding and TIG welding. And correspondingly, the root openings are 3, 4 and 2.8㎜. The results of the tensile test of weld HAZ come out electric shield arc welding > CO₂ gas arc welding > TIG welding in case of single welding. It is believed that this is a phenomenon where difference of its root opening or base metal thickness. Also, the technique of AE is ideally suited to study variables which control time and stress dependent fracture or damage process in metallic materials.

SWS 490A 강의 용접 열영향부 음향방출 특성에 대한 연구(1)

이장규,우창기,박성완,윤종희,조진호,김봉각,구영덕 한국공작기계학회 2004 한국생산제조학회지 Vol.13 No.4

The object of this study is to investigate the effect of compounded welding through the AE(Acoustic Emission) characteristics for weld HAZ(Heat Affected Zone) under the static tensile test. This study was carried out an SWS 490A, high tension steel for electric shield metal arc welding(SMAW), CO₂gas arc welding and TIG welding. Data displays are based on the measured parameters of the AE signals, along with environmental variables such as time and load. The accumulated AE event curve of HAZ definitely have the point of inflection subject to tensile test. The results of the tensile test of HAZ come out electric shield arc welding > CO₂ gas arc welding >TIG welding in case of single welding, but generally the tensile test of HAZ come out electric shield arc welding > TIG welding > CO₂ gas arc welding. These history plots give us useful and powerful information to analyze the results of material evaluation testing.

미세절제술과 비교 유전자 보합법에 의한 각종 종양에서의 유전자 변화에 관한 연구

구선회,신소영,임춘화,전영미,이윤이,김진만 충남대학교 의과대학 지역사회의학연구소 2000 충남의대잡지 Vol.27 No.2

For the evaluation of oncogenesis, progression and prognosis of cancer, CGH is an important technique, because this technique is economic due to utilization of only one probe and lack of culture, screening mathod of whole genome and possibility of retrospective and prospective study. By the CGH, genornic variation of 20 breast cancer tissues, 23 stomach cancer tissues and 16 bladder cancer tissues were analyzed. The results were as followes ; 1. breast cancers The CGH results showed gains on chromosomes 8q(40%), lq(30%), 17q(15%), 20q(15%), 18q (15%), 5p(15%), and 13q(15%). The Deletions were on chromosomes 17p(45%) and 22q(20%). High-level amplifications(green/red ratio >1.5) were noted on chromosomes 1p31, iq, 3q25-qter, 5p, 7q31-qter, 8q, 9q22-qter, 10p, l1p, 11q22-qter, 12p, 12q24, 14g21-qter, 15q23-qter, 17q, 18p, 18q12-qter, 20p, and 20q. By comparison with infiltrating ductal carcinoma, the two medullary carcinomas showed high-level amplification on chromosomes iq3l, lq, 8q, 10p, 11p and 12p. 2. stomach cancers 1) Usual amplification sites of genome were lq, 13q, 17q, 20p,q. 2) 17p was the most common deletion site. The other sites of the deletion were lq, 4q. 3) In intestinal type of stomach cancer, genomic variation is more common than diffuse type. 4) In the cases of no evidence of lymph node metastasis, deletion of 17p is absent but amplification of 8q is obvious in the case of lymph node metastasis. 3. bladder cancers Common amplification of copy numbers of DNA sequences by CGH were seen at 1q, 3q, 4q, 5p, 6pq, 7p, 8q, 11q, 12q, 13q, 17q, 18q and 20pq(more than 20% of cases). High level amplification was noted at 1p32, 3p2l, 3q24, 4q26, 8q21-ter, 11q14-22, 12q15-21, 12q21-24, 13q 21-31, 17q22, and 18q22. Deletions were noted at 2q21-qter, 4q13-23, 5q, 8p12-22, 9pq, 11p13-15 (more than 20% of cases).

자가 골수 기질세포이식을 이용한 대퇴골두의 무혈성 괴사 및 장관골 골낭종의 치료

이승구,권순용,정진화,정도현,이주형,최숭욱 대한정형외과학회 골.연부조직이식학회 2003 대한골.연부 조직이식학회지 Vol.3 No.2

실리콘 반도체 에칭기술개발 동향에 관한 조사연구

신영두,이진구 동국대학교 산업기술환경대학원 1994 산업기술논총 Vol.2 No.-

This paper describes investigation and analysis of Si wafer find-line processes from 1960's up to present based on U.S. Patent No. 4,941,941 entitled " METHOD OF ANISOTROPICALLY ETCHING SILICON WAFERS AND WAFER ETCHING SOLUTION". This study is intended to classify techniques on wet etchants from chemicals mainly used in the reference above and 9 patents, and also includes reviews on both physical and chemical features of wet etching and, further more, comparative explanation of wet and dry etching. The characteristics of low temperature and low speed, of the wet etching processes and some limitations of the informations, given in U.S. Patent No. 4,941,941 and 9 patents, are mainly investigated and analysed, and, then, the dry etching processes are simply discussed as a substitution for the fin-line Si processes. And, finally, future possible development of other kinds of chemical etchants is suggested.

고속의 GaAs SRAM 을 위한 새로운 센스 앰프의 설계 연구

조희철,김선옥,이웅호,윤진섭,이진구 동국대학교 산업기술대학원 1993 산업기술논문집 Vol.1 No.-

A new sense amplifier is designed in order to realize high-speed GaAs SRAM's. The Schematics are similar to "a source coupled differential amplifier" execept that two analyzed using basic FET current equations. The transconductance of the new sense amplifier is approximately 3.5 times larger than that of the conventional sense amplifier. Output high voltage is reduced to about 0.64V, therefore, the time which reached V_(max) are reduced also. The simulation results show that the access time of 0.9ns and the power dissipation of 12.2mW are achieved in GaAs 16bit SRAM's.

優良室素固定菌의 探索分離 및 生理的 特性

朴愚喆,李光熙,金進鎬,李麟九,曺晋基 慶北大學校出版部 1987 慶北大農學誌 Vol.5 No.-

This experiment was conducted to search for Rhizobia with good nitrogen fixation abilities and to investigate their physiological characteristics isolated from 12 soybean cultivars and the affinities of root nodule bacteria with soybeans. The results obtained were as follows ; Based on colors, Rhizobia grown on YMA medium were divided into 3 groups, i. e., white, translucent and transparent, amounting to 60, 30 and 10%, respectively. In litmus milk reation, the strains which produced alkali, acid serum, alkaline serum and acid reached to 51, 29, 9 and 11%, respectively. Strains, S022, and S096 were slow-growers and produced alkaili, while strains, S080, S090, and S118 were fastgrowers and produced acid. The growth of root nodule bacteria on YMA medium was favorable between the initial pHs of 6.0~7.0. Glutamine, asparagine and allantoin as nitrogen sources enhanced the growth of root nodule bacteria. All the strains tested formed nodules on the soybean roots, and the strains with good symbiotic nitrogen fixation abilities that had white color, small colony, nitrate reduction abilities and no nitrite reduction abilities showed comparatively high nitrogen fixing activities. Some strains varied in nitrogen fixing activities according to soybean cultivars, and a few strains formed ineffective nodules which showed no nitrogen fixing activity.

GaN MMIC를 위한 R, L, C 및 Thru Line 수동소자 제작

윤관기,유순재,이진구 선문대학교 1999 공과대학논문집 Vol.1 No.2

Ku -band 전력용 GaN MESFET 소자를 사용하는 전력증폭기 MMIC 설계 및 제작을 위한 Sapphire 기판위에 인덕터, 캐패시터, 저항 및 전송선로의 수동소자를 제작하였다. 직사각형 나선 인덕터, MIM 캐패시터, Ti을 이용한 금속저항 및 Thru 전송선로를 제작하였다. 제작한 직사각형 나선 인덕터는 12-18 GHz의 주파수 범위에서 0.2~5 nH 인덕턴스를 얻었으며, MIM 캐패시터에서 0.1~38.5 pF, Ti 금속저항에서 87Ω -2,235Ω을 얻었다. 또 Thru 전송선로는 Insertion Loss 약 0.2 dB, 입력 반사계수는 -30 dB를 얻었다. Ku-band MMIC passive devices of inductor, capacitor, resistor and thru line were fabricated on the sapphire to design the MMIC with GaN MESFET. Rectangular spiral inductor, MIM capacitor, Ti metal resistor and thru line were tested. It was measured that inductance of rectangular spiral inductors were 0.2~ 5 nH at 12~18 GHz, capacitance of MIM capacitors were 0.1~38.5 pF, resistance of Ti-resistors were 87~ 2235Ω, respectively. And the thru line with insertion loss 0.2 dB and input reflection index -30 dB was measured.

Waveguide VCO using GaAs Gunn diode for FMCW radar at 94 ㎓

Jin-Ho Kim,Dong-Sik Ko,Yong-Hyun Baek,Sang-Jin Lee,Seok-Gyu Choi,Min Han,Tea-Jong Beak,Yeon-Sik Chae,Jin-Koo Rhee 대한전자공학회 2010 ICEIC:International Conference on Electronics, Inf Vol.1 No.1

In this paper, a 94 ㎓ waveguide voltage controlled oscillator (VCO) is designed and fabricated. We fabricated the waveguide VCO, which has a good linearity, low phase noise and high output power. The oscillating frequency is tuned by resonant disc and output power is optimized by back-short. A cavity, bias posts and a magic tee are designed to get good performances. The bandwidth is 1.015 ㎓ from 93.865 to 94.880 ㎓ and output power is from 11.15 to 12.46 ㏈m. It has 0.91 % of linearity in 415 ㎒ from 93.910 to 94.325 ㎓. Phase noise is -102.82 ㏈c/㏈ at 1 ㎒ offset.

Comparison Studies on GaAS Ohmic Contacts Fabricated by Rapid and Conventional Alloying Process and New Analysis Method of TLM Patterns

Rhee, Jin-Koo 대한전자공학회 1988 전자공학회논문지 Vol. No.

Ohmic contact process for the fabrication of GaAs integrated circuits is very important. Specific contact resistivities, assuming Rsm=Rs, were measured after the rapid and the conventional alloying process, respectively. The results show that the characteristics of ohmic contact through the rapid alloying process is much better (Apc=1.3~3.3x10**-7 \ulcorner-(m\ulcorner. This is probably due to intensive and compound energy densities during the rapid alloying process. New analysis method of TLM patterns viz. measurements of normlaized specific contact resistivities are proposed to reduce measurement errors that could occur when measuring the small contact end resistances. The adoption of rapid alloying process for the mass production of GaAs integrated circuits could greatly reduce the total processig time.