Secant 법에 의한 전파흡수체의 정합경계값 계산

裵圭植 수원대학교 산업기술연구소 1994 산업기술연구소논문집 Vol.9 No.-

The common electromagnetic wave absorbers consist of a magnetic material layer bonded to a metal plate at the back. For such structure, a theoretical equation involving six parameters defines the allowable material and configuration parameters that will produce zero reflection or practically 99% or more absorption (20 dB attenuation). This complex equation can only be solved numerically. A numerical algorithm based on the Secant method was developed to compute the matching boundary values corresponding to 20 dB attenuation. This method applicable to any six parameters effectively yielded accurate solutions within the least iterations.

어떤 흰쥐 뇌에서 부신절제가 전기경련 충격에 의한 조기유전자 발현에 미치는 영향

하규섭,강웅구,정희연,주연호,조수철,박주배,김용식 大韓神經精神醫學會 1996 신경정신의학 Vol.35 No.4

부신피질 호르몬이 70g 이내의 어린 흰쥐의 뇌에서 전기경련 충격에 의한 조기유전자(IEG)의 발현에 미치는 급성 효과 및 만성 효과를 살펴보기 위하여 본 연구를 수행하였다. 70g 이내의 생식선이 발달하지 않은 수컷 Sprague-Dawley 흰쥐에서 양측 부신을 절제한지 3일과 14일 후에 전기경련 충격으로 경련을 유발시켜 대뇌 피질과 해마에서 c-fos, jun B, TIS 1 의 발현 양상을 관찰하고 이를 대조군과 비교하여 다음과 같은 결과를 얻었다. 1) 부신절제 후 대뇌 피질에서 전기경련 충격에 의한 c-fos와 jun B mRNA 발현은 일찍 최대치에 도달하고 일찍 감소하는 경향을 보였으며, 초기의 발현이 강화되는 경향을 보였다. 이러한 경향은 jun B가 c-fos 보다 뚜렷하였으며, 부신절제 후 3일이 경과된 경우보다 14일이 경과된 경우가 뚜렷하였다. 2) TIS 1의 경우에는 대뇌 피질에서 이러한 초기 발현의 강화가 관찰되지 않았으며, 부신절제 14일된 어린 흰쥐에서만 발현이 억제되는 경향을 보였다. 3) 부신절제는 해마에서는 전기경련 충격에 의한 c-fos와 jun B의 발현에 영향을 미치지 않았다. 부신절제 3일 후 전기경련 충격에 의한 TIS 1의 발현은 억제되는 경향이 관찰되었으나, 부신절제 14일 후에는 이러한 경향이 관찰되지 않았다. 이상의 결과로부터 부신절제는 전기경련 충격에 의한 IEG의 발현에 영향을 미치며, 그 영향은 흰쥐의 뇌의 부위, IEG의 종류에 따라 차이가 있음을 알수 있었고, 흰쥐의 연령 및 부신피질 호르몬을 제거한 기간 등의 영향도 있음을 확인할수 있었다. To evaluate the influences of adrenocortical hormone on the signal transduction system in young brain, the authors observed the effects of bilateral adrenalectomy on the induction of immediate early genes(IEGs) such as c-fos, jun B, and TIS 1 by electroconvulsive shock(ECS) in the young rats. The young(70g) male Sprague-Dawley rats were treated with ECS(130V, 0.5sec) at day 3 or 14 after bilateral adrenalectomy. They were sacrificed at 0, 15, 30, 45, and 60 minutes after ECS and cerebral cortex and hippocampus were dissected from their brans . The induction of IEGs were assessed with northern by hybridization. The band intensities of the autoradiographs measured by densitometer were compared between adrenalectomized group and sham-operated control group. In the cerebral cortex, c-fos and jun B appeared and disappeared earlier, and enhanced in the earlier phase of the induction in the adrenalectomized group. These trends were more prominent for jun B than for c-fos, and were more prominent at day 14 than at day 3 after adrenalectomy. The induction of TIS 1 was attenuated at day 14 after adrenalectomy. In the hippocampus, the induction of c-fos and jun B by ECS was not influenced by adrenalectomy. The induction of TIS 1 was attenuated at day 3 after adrenalectomy. These results suggest that adrenalectomy has influences on the induction of IEGs by ECS in rat brain differently, depending on the brain region, the kind of IEGs, the age of the rats, and the time passed after adrenalectomy.

부신절제가 전기경련 충격에 의한 흰쥐 뇌의 조기유전자 발현에 미치는 영향

하규섭,강웅구,정희연,주연호,박주배,김용식 大韓神經精神醫學會 1996 신경정신의학 Vol.35 No.4

부신피질 호르몬이 뇌에서 전기경련 충격(ECS)에 의한 조기유전자(IEG)의 발현에 미치는 영향을 살펴보기 위하여 본 연구를 수행하였다. 양측 부신을 절제한 수컷 Sprague-Dawley 흰쥐에서 부신을절제한 지 3일 후에 ECS로 경련을 유발시켜 대뇌 피질, 해마 및 소뇌에서 c-fos, jun B, TIS 1의 발현 양상을 관찰하고 이를 대조군과 비교하여 다음과 같은 결론을 얻었다. 1) 부신절제 후 대뇌 피질에서 ECS에 의한 c-fos와 jun B 및 TIS 1 mRNA 발현은 대조군에 비하여 억제되었다. 2) 해마와 소뇌에서는 IEG의 종류에 상관없이 부신절제가 ECS에 의한 IEG의 발현에 별 영향을 미치지 않았다. 이상의 결과로부터 부신절제는 ECS에 의한 IEG의 발현에 영향을 미치며, 그 영향은 뇌의 부위에 따라 다름을 확인할 수 있었다. 부신피질 호르몬이 IEG 발현에 영향을 미치는 기전에 대하여 고찰하였다. The adrenocortical hormones have been known to be related with the pathogenesis of mental disorders and individual vulnerability to stress. To evaluate the influences of adrenocortical hormone on the signal transduction system in rat brain, the authors observed the effects of bilateral adrenalectomy on the induction of immediate early genes(IEGs) after electroconvulsive shock(ECS). Male Sprague-Dawley rats(200 - 250g) were treated with ECS(130V, 0.5sec) at day 3 after bilateral adrenalectomy. Rats were sacrificed at 0, 15, 30, 45, and 60 minutes after ECS, and cerebral cortex, hippocampus, and cerebellum were dissected from the brain. The induction of IEGs was assessed with northern hybridization. The band intensities of the autoradiographs measured with densitometer were compared between adrenalectomized group and sham-operated control group. After adrenalectomy, the c-fos, jun B, and TIS 1 induction by ECS was generally attenuated in the cerebral cortex. The induction of IEGs in the hippocampus and in the cerebellum was not influenced by adrenalectomy. These results suggest that adrenalectomy has differential influences on the induction of IEGs by ECS in the rat brain depending on the region of brain.

Influence of Compliance on the Cyclic Behavior of Solder Joints in Surface-Mounted Electronic Packages

Bae, Kyoo Sik 수원대학교 산업기술연구소 1992 산업기술연구소논문집 Vol.7 No.-

컴플라이언스가 표면실장패키지에 사용되는 63Sn-37Pb 땜납접합의 주기거동에 미치는 영향을 기계적 피로실험을 통해 연구하였다. 주기거동 진행과정은 미소균열의 생성과 성장에 따르는 Ⅰ단계와 거시균열성장과 관련된 Ⅱ단계로 나타났다. 탄성 컴플라이언스의 증가는 단계 Ⅱ를 줄이고 단계 Ⅰ를 늘리는 역할을 하였는데, 이는 초기소성변형량이 작았기 때문이다. 단계 Ⅰ의 증가는 피로수명의 증가를 가져왔으나, 단계 Ⅱ의 축소는 접합의 급작스런 파괴의 원인이 되었다.

무연솔더 범프 접촉 탐침 핀의 Sn 산화막 형성 기제

배규식,Bae, Kyoo-Sik 한국재료학회 2012 한국재료학회지 Vol.22 No.10

In semiconductor manufacturing, the circuit integrity of packaged BGA devices is tested by measuring electrical resistance using test sockets. Test sockets have been reported to often fail earlier than the expected life-time due to high contact resistance. This has been attributed to the formation of Sn oxide films on the Au coating layer of the probe pins loaded on the socket. Similar to contact failure, and known as "fretting", this process widely occurs between two conductive surfaces due to the continual rupture and accumulation of oxide films. However, the failure mechanism at the probe pin differs from fretting. In this study, the microstructural processes and formation mechanisms of Sn oxide films developed on the probe pin surface were investigated. Failure analysis was conducted mainly by FIB-FESEM observations, along with EDX, AES, and XRD analyses. Soft and fresh Sn was found to be transferred repeatedly from the solder bump to the Au surface of the probe pins; it was then instantly oxidized to SnO. The $SnO_2$ phase is a more stable natural oxide, but SnO has been proved to grow on Sn thin film at low temperature (< $150^{\circ}C$). Further oxidation to $SnO_2$ is thought to be limited to 30%. The SnO film grew layer by layer up to 571 nm after testing of 50,500 cycles (1 nm/100 cycle). This resulted in the increase of contact resistance and thus of signal delay between the probe pin and the solder bump.

NiSi 접촉과 Cu 플러그/Ti 확산방지층의 동시 형성 연구

배규식,Bae, Kyoo-Sik 한국재료학회 2010 한국재료학회지 Vol.20 No.6

As an alternative to the W plug used in MOSFETs, a Cu plug with a NiSi contact using Ta / TaN as a diffusion barrier is currently being considered. Conventionally, Ni was first deposited and then NiSi was formed, followed by the barrier and Cu deposition. In this study, Ti was employed as a barrier material and simultaneous formation of the NiSi contact and Cu plug / Ti barrier was attempted. Cu(100 nm) / Ti / Ni(20 nm) with varying Ti thicknesses were deposited on a Si substrate and annealed at $4000^{\circ}C$ for 30 min. For comparison, Cu/Ti/NiSi thin films were also formed by the conventional method. Optical Microscopy (OM), Scanning Probe Microscopy (SPM), X-Ray Diffractometry (XRD), and Auger Electron Microscopy (AES) analysis were performed to characterize the inter-diffusion properties. For a Ti interlayer thicker than 50 nm, the NiSi formation was incomplete, although Cu diffusion was inhibited by the Ti barrier. For a Ti thickness of 20 nm and less, an almost stoichiometric NiSi contact along with the Cu plug and Ti barrier layers was formed. The results were comparable to that formed by the conventional method and showed that this alternative process has potential as a formation process for the Cu plug/Ti barrier/NiSi contact system.

임상연구 : Propofol을 사용한 전신마취 시 비만이 각성에 미치는 영향

조인배 ( In Bae Cho ),김상영 ( Sang Young Kim ),김동옥 ( Dong Ok Kim ),최영규 ( Young Kyoo Choi ),김건식 ( Keon Sik Kim ) 대한마취과학회 2006 Korean Journal of Anesthesiology Vol.50 No.4

Background: Recently obesity population is epidemically rapidly increasing. But, in the anesthetic field the study for obesity patients is not good enough. So, we designed the study to see the effect of obesity on awareness in general anesthesia with propofol. Methods: The 52 subjects were between 20 to 60 years old and ASA physical status 1, 2 undergoing general anesthesia for elective surgery. According to asia pacific obesity criteria, we divided the patients into the obesity group (BMI ≥ 25) and the non-obesity group (BMI < 25). Propofol was infused using TCI for induction and maintenance. BIS was used for monitoring the depth of anesthesia. During operation, we tried to keep BIS between 40-49 by manipulate the target concentration of TCI. After the operation, without stimulating patients, we measured the time (T-BIS5070) from the BIS passes 50 then goes to 70. We compare the T-BIS5070 between the obesity and the non-obesity group. Results: The obesity and the non-obesity group do not show significant difference in age, sex, height, body temperature, anesthesia time, and total used propofol amounts. BMI in obesity group was 27.3 ± 1.9 kg/m2 and in non-obesity group was 22.2 ± 1.8 kg/m2. T-BIS5070, the awareness time was significantly different between the obesity group (170.3 ± 54.8 sec) and the non-obesity group (212.7 ± 81.8 sec). Conclusions: Our data suggest that in general anesthesia with propofol the obesity group`s awareness time is shorter compared with the non-obesity group and the effects may come from the uniqueness of the propofol`s pharmacokinetics and the obesity patient`s physical characteristics. (Korean J Anesthesiol 2006; 50: 379~84)

이론분석에 의한 MEMS 소켓 핀의 스프링 상수 계산

배규식,호광일,Bae, Kyoo-Sik,Ho, Kwang-Il 한국재료학회 2008 한국재료학회지 Vol.18 No.11

Spring constants (displacement per unit applied load) of MEMS socket pins of given structures were computed by theoretical analysis and confirmed by the finite element method (FEM). In the theoretical analysis, the displacement of pins was calculated based on the 2-dimensional bending theory of the curved beam. For the 3-dimensional modeling, CATIA was used. After modeling, the raw data were transferred to ANSYS, which was employed in the 3-dimensional analysis for the calculation of the stress and strain and loaddisplacement The theoretical analysis and the FEM results were found to agree, with each showing the spring constants as 63.4 N/m within a reasonable load range. These results show that spring constants can be easily obtained through theoretical calculation without resorting to experiments and FEM analysis for simple and symmetric structures. For the some change of shape and structural stiffness, this theoretical analysis can be applied to MEMS socket pins.

An Effective Frame Design by Large-Step Markov Chain

Park,Sung Kyoo,Kim,Yong Bae,Lee,Yun Sik 대한전자공학회 1997 ICVC : International Conference on VLSI and CAD Vol.5 No.1

In mask frame design, some special-purpose cells have to be placed on the restricted sawing lines without violating given constraints. In many cases, it is not always possible to place all required cells on the restricted sawing lines. In this paper, we solve the optimal frame placement problem using large-step Markov chain(LSMC) approach. A preliminary result shows a visible performance improvement over a previous deterministic, heuristic.

자동차 부품용 강재(SM40C)의 마찰용접 최적화와 AE에 의한 실시간 품질평가에 관한 연구

오세규(Sae Kyoo Oh),박종배(Jong Bae Park),공유식(You Sik Kong) 한국해양공학회 1999 韓國海洋工學會誌 Vol.13 No.1

This paper presents the experimental examinations and statistical quantitative analysis of the correlation between the cumulative counts of acoustic emission(AE) during plastic deformation periods of the welding and the tensile strength and other properties of the bar-to-bar welded joints of O.D. 16㎜ shaft(SM40C) as well as the various welding variables. And this is a new approach which attempts finally to develop real-time quality monitoring system for friction welding. The results lead to a practical possibility of real-time quality control more than 100% joint efficiency showing good weld with no micro structural defects.