레이저 다이오드 측면 여기 녹색레이저의 출력특성

김병태 청주대학교 산업과학연구소 1998 産業科學硏究 Vol.16 No.-

An intracavity frequency doubled Nd YAG laser with KTP (green laser) side-pumped by a Laser-Diode bar array was designed and fabricated. To get the optimized resonator condition the folded angle, which was made between Nd YAG rod and KTP crystal, obtained was 34˚. A laser output energy of 2.1 ml with an efficiency of 1.43% was obtained at a wavelength of 532 nm.

공간필터의 상전송에 의한 레이저 빛살 특성에 관한 연구

김병태 청주대학교 산업과학연구소 2006 産業科學硏究 Vol.23 No.2

The suppression of the high frequency at the spatial beam profile is very important to develop the high power laser system. The high frequency at the laser beam is growing due to the nonlinearity of the laser medium according as the laser intensity increases, the result is that the medium is broken. The spatial filter plays an important part to remove the high frequency for the protection of the optical medium, and to gain a high energy effectively.

반도체레이저 여기 세라믹 Nd:YAG 레이저의 펄스 모드 발진

김병태 청주대학교 2018 産業科學硏究 Vol.36 No.1

A laser-diode pumped Nd:YAG ceramic laser was developed for optimum condition of oscillator using pulse output characteristics. The output energy was measured 7.9 mJ with an output coupler reflectivity of 77 % under a pumping energy of 17.9 mJ, and a pulse duration of 1,000 ㎲. A output efficiency of 44.1 % and a slope efficiency of 48.6 % were obtained. The optimum delay time was measured as 985 ㎲ for Q-switch operation, and the output energy was obtained as 0.35 mJ with an output pulse width of 4.3 ㎱.

이온주입이 금속의 일함수에 미치는 영향(Ⅰ)

김현경,강석태,황정남,이철주,최대선,정병두 연세대학교 자연과학연구소 1984 學術論文集 Vol.13 No.-

이온 주입이 일함수 차이에 미치는 영향을 연구하기 위하여 낮은 에너지 이온 가속기, 전자총과 기타 일함수 차이를 측정하기 위한 장치를 설계, 제작하였다. 제작된 이온 가속기의 집속 특성은 이론적인 값과 일치하였다. 즉, 집속 렌즈의 확대율이 이론값은 2.0인데 비하여 1.2로 상당히 작은 값이었다. 또한 집속 렌즈의 전압 V_L과 추출 전압 V_e에 의한 집속 특성 역시 이론값과 매우 잘 일치하였다 . 제작된 장치를 사용하여 다결정 Cu와 Ni의 일함수 차이를 측정한 결과 0.45eV임을 알았다. 그리고 전자선을 이용하여 억제 전위차로 일함수를 측정할때 입사 전자의 반사율을 고려해야 함을 알았다. Low energy ion accelerator, electron gun, and apparatus for measuring work function difference are designed and constructed in order to study the effect of ion implantation on the work function. The focusing properties of accelerator is coincided with theoretical results; the magnification of Einzel lens is found to be 1.2, while theoretical value is 2.0, and the focal properties as a function of V_L/V_e are in good agreement with theory. Using these systems, the work function difference between polycrystalline Cu and Ni is found to be 0.45eV, and the experimental retarding potential plots indicate close agreement with the theoretical values modified by electron reflection.

KDP 결정 내부의 온도 기울기가 열파괴에 미치는 영향

김병태 청주대학교 산업과학연구소 2001 産業科學硏究 Vol.19 No.1

In case of the KDP crystal is used as a harmonic generation material, the thickness of KDP is decided in accordance with an efficient frequency conversion under the laser intensity at a low average power laser. But the thermal destruction of crystal, which is owing to the temperature difference between the surface and the inside, have to be under consideration in case of a high average power laser The limitation of the laser power was taken to the KDP thickness at the harmonic generation of high average power laser

분할한 KDP 결정에서의 고조파 변환에 관한 연구

김병태 청주대학교 산업과학연구소 2003 産業科學硏究 Vol.21 No.1

The stacked KDP crystal was used to compensate for the decrease of conversion efficiency owing to the temperature rising at the crystal in case of a high average power laser. The conversion efficiency was about the same. Only for the dispersion of the refractive index was under consideration, the air cooling was more desirable than the liquids at the stacked KDP crystal.

턴디슈용 SiC 코팅材의 특성에 관한 硏究

김행식,최태현,이용구,전병세 경남대학교 신소재연구소 1995 論文集 Vol.5 No.-

턴디쉬 내장용으로 사용할 내화재료의 여러 가지 특성들을 시험하였다. 납석 70%, 점토 10% 그리고 탄화규소 20%을 혼합하여 18 가지의 조성을 가지는 시험편을 제조하였다. 탄화규소는 각각 순도 85%와 65%인 유럽산, 일본산, 중국산을 택하여 최종 제품에 미치는 영향을 알아보았다. 여러 가지 시험의 결과 10% 탄화규소를 포함한 시험편의 경우 점토질 내화벽돌 보다 수명이 2배 정도 향상되었으며 차지당 용손 두께도 1.5∼1.7㎜/ch였다. Various properties of refractory materials for the tundish lining were examined. The refractory samples with 18 different composition were prepared by mixing powders of 70 wt.% pyrophyllite. 10 wt.% clay and 20 wt.% Sic. SiC was selected from three sources, European. Japanese and Chinese-made, having 85% and 65% purities, to examine their effects on the final properties. As a results of several testings. the sample with 10% SiC(European1 was best suitable for tundish lining as a refractory coating materials. The wear depth was 1.2-1.5 mm per charge at the wall and 1.7 mm per charge a t the slag line, having shown that this service life was about 2 times longer than the ordinary lining made of clay firebricks(SiO₂-Al₂O₃).

生化學的 檢定方法에 依한 種子의 發芽力檢定에 관한 硏究

全炳台,全遇滂,金大鎭 건국대학교 1977 論文集 Vol.5 No.1

In order to determine and to reduce the differences between enzymatic reduction method utilizing T.T.C. (2,3,5, Triphenyl tetrazolium chloride) and ordinary terminator method, a series of color reaction was carried out and showed the differences. When a series of color reaction was divided into several parts, following results were obtained. 1.When a series of color reaction using Barley, Wheat, and Corn, was carried out, garminable seeds showed following results. (1) Embryo completely stained Red (2) Both ending Scutellium unstained (3) Extreme tip of Radicle unstained 2.When a series of color reaction using Soybean and Radish was carried out, terminable seeds showed following results. (1) Seed completely stained Red (2) Cotyledon minor unstained (3) Radicle tip minor unstained 3.Without color reaction using Barley, Wheat and Corn, it showed non-germination. In case of color reaction non-gerinable seeds showed following results. (1) Plumle unstained (2) Radlcle, Coleorizer and Root-cap unstained (3) Hypocotyle and Seminal-root unstained (4) Scutellium completely unstained (5) Scutellium completely unstained (6) Embryo stained faint pink 4.Without color reaction using Soybean and Radish, it showed non-germination in case of color reaction non-terminable seeds showed following results. (1) More than one-half of Radicle unstained (2) Unstained area near Point of attachment of Radicle and Plumule. (3) Spottal area of Radicle unstained (4) More than one-hlaf of Cotyledon unstained (5) Seed stained faint pink

분산 컴퓨팅 환경에서의 이동 에이전트 보안 구조

이병래,김태우 高麗大學校附設 컴퓨터科學技術硏究所 1999 JOURNAL OF COMPUTER SCIENCE & ENGINEERING TECHNOLO Vol.2 No.-

이동 에이전트 기반의 분산 컴퓨팅 환경에서 에이전트의 안전한 수행을 보장하기 위해 인증과 접근 제어를 제공하는 보안 서비스가 제공되어야 한다. 이러한 보안 서비스는 에이전트의 이동성을 고려해 여러 보안 도메인(Security Domain)에서도 효율적으로 이루어져야 한다. 본 논문에서는 MASIF를 기반으로 CORBA 보안 서비스를 이용하여 이동 에이전트 보안 구조를 제안하였다. 분산 에이전트 환경에서의 키 분배 문제를 해결하기 위하여 공개키 기반 구조를 MASIF에 적용하였으며 제안된 인증과 접근 제어 기법으로 에이전트 플랫폼에서의 보안 구조를 성립하였다 제안한 구조는 MASIF에 기반하기 때문에 다른 에이전트 플랫폼과의 호환성을 가진다. To guarantee safe execution of mobile agents in distributed agent environment, authentication and authorization security service must be provided. These security service should be efficiently applied across multiple security domains In this paper, based on CORBA security service specification[2], we propose the security service architecture for MASIF[1]-based mobile agent system. PKI is implemented to eliminate key distribution problem in distributed agent environment, the security architecture is established by proposed authentication and authorization mechanisms in agent platforms. Since proposed security architecture based on MASIF, it is interoperable with other mobile agent platforms

말초혈액 내 백혈구수와 대사증후군과의 연관성

황상태,김범수,황상준,서정열,김병진,이원영,성기철,강진호,김선우,이만호,박정로 대한순환기학회 2004 Korean Circulation Journal Vol.34 No.3