• 한국방사선학회논문지
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• 제13권6호
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• pp.895-900
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• 2019

초음파는 인체에 무해하다고 알려져 산부인과에서 태아의 진단 및 발육상태 확인을 위해 널리 이용되고 있다. 진단 초음파의 장시간 사용은 체온 변화를 야기할 수 있지만 초음파로 인한 임신부의 자궁온도 변화에 대한 연구가 부족한 실정이다. 이에 본 연구에서는 자체 제작한 자궁모형팬텀을 이용하여 초음파 주사시간에 따른 온도 변화를 알아보고자 하였다. 조직등가 물질인 아크릴과 돼지 자궁을 이용하여 인체 자궁과 유사한 자궁모형팬텀을 자체 제작하였으며 초음파 장비와 4MHz convex probe를 사용하였다. 아크릴 수조 내부, 자궁내부, 대기온도 측정을 위해 3개의 탐침형 온도계를 설치하였고 측정대상의 온도를 분단위로 6시간, 총 361회 측정 한 결과 자궁모형팬텀의 온도가 상승되었음을 확인하였다. 본 연구를 통해 초음파로 인한 인체 체온 상승의 가능성을 확인 할 수 있었고 본 연구가 초음파 열 흡수효과 연구의 기초자료로 활용 될 것이라 사료된다.

• Bulletin of the Korean Chemical Society
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• 제33권12호
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• pp.4063-4068
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• 2012

Oxide substrates in semiconductor-sensitized solar cells (SSSCs) have a great impact on their performance. $TiO_2$ has long been utilized as an oxide substrate, and other alternatives such as ZnO and $SnO_2$ have also been explored due to their superior physical properties over $TiO_2$. In the development of high-performance SSSCs, it is of significant importance to understand the effect of oxides on the electron injection and charge recombination as these two are major factors in dictating solar cell performance. In addition, elucidating the relationship between these two critical processes and solar cell performance in each oxide is critical in building up the basic foundation of SSSCs. In this study, ultrafast pump-probe laser spectroscopy and open-circuit decay analysis were conducted to examine the characteristics of three representative oxides ($TiO_2$, ZnO, and $SnO_2$) in terms of electron injection kinetics and charge recombination, and the implication of results is discussed.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1996년도 춘계학술대회
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• pp.216-216
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• 1996

The purpose of the present study was to determine whether in vivo noradrenergic neural activity in the locus coeruleus is related to the development of hypertension. Two groups of animals were prepared, 1) young spontaneously hypertensive rats (SHR) and 2) age-matched normotensive wistar kyoto rats (WKY). At il weeks of age, the release of norepinephrine (NE) and 3,4-dihydroxyphenylglycol (DOPEG) from locus coeruleus of young SHR and WKY as an index of neural activity were determined by in vivo microdialysis along with blood pressure (BP) at three conditions : 1) normal; 2) elevated BP by systemic injection of phenylephrine and 3) alpha-1 adrenoceptor stimulated by perfusion of phenylephrine into the locus coeruleus through microdialysis probe. Basal releases of NE and DOPEG from the iocus coeruleus were 0.415+/-0.089pg/20min, 1.311+/-0.293 pg/20min in SHR and 0.204+/-0.078 pg/20min, 1.492+/-0.365 pg/20min in WKY respectively. Basal release of NE from the locus coeruleus of SHR was significantly greater than that of WKY. Phenylephrine systemic injection caused elevation of BP in both SHR and WKY in a dose related manner. Following phenyephrine injection, the releases of NE and DOPEG from the locus coeruleus of SHR were significantly decreased, whereas there were no significant changes in the releases of NE and DOPEG In young WKY. Alpha-1 adrenoceptor stimulation in the locus coeruleus by perfused phenylephrine through microdialysis probe caused pressor responses in both SHR and WKY, but the magnitude of pressor response in SHR was larger compared with that in WKY. The result from the present study suggests that noradrenergic neural activity in locus coeruleus may contribute as one of triggering factors for the expression of hypertension in young SHR.

• Journal of Mechanical Science and Technology
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• 제16권9호
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• pp.1121-1136
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• 2002

The flow characteristics of film coolant issuing into turbulent boundary layer developing on a convex surface have been investigated by means of flow visualization and three-dimensional velocity measurement. The Schlieren optical system with a spark light source was adopted to visualize the jet trajectory injected at 35° and 90° inclination angles. A five-hole directional pressure probe was used to measure three-dimensional mean velocity components at the injection angle of 35°. Flow visualization shows that at the 90° injection, the jet flow is greatly changed near the jet exit due to strong interaction with the crossflow. On the other hand, the balance between radial pressure gradient and centrifugal force plays an important role to govern the jet flow at the 35° injection. The velocity measurement shows that at a velocity ratio of 0.5, the curvature stabilizes downstream flow, which results in weakening of the bound vortex structure. However, the injectant flow is separated from the convex wall gradually, and the bound vortex maintains its structure far downstream at a velocity ratio of 1.98 with two pairs of counter rotating vortices.

• JSTS:Journal of Semiconductor Technology and Science
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• 제14권2호
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• pp.202-211
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• 2014

The bulk current injection (BCI) and direct power injection (DPI) method have been established as the standards for the electromagnetic susceptibility (EMS) test. Because the BCI test uses a probe to inject magnetically coupled electromagnetic (EM) noise, there is a significant difference between the power supplied by the radio frequency (RF) generator and that transferred to the integrated circuit (IC). Thus, the immunity estimated by the forward power cannot show the susceptibility of the IC itself. This paper derives the real injected power at the failure point of the IC using the power transfer efficiency of the BCI method. We propose and mathematically derive the power transfer efficiency based on equivalent circuit models representing the BCI test setup. The BCI test is performed on I/O buffers with and without decoupling capacitors, and their immunities are evaluated based on the traditional forward power and the real injected power proposed in this work. The real injected power shows the actual noise power level that the IC can tolerate. Using the real injected power as an indicator for the EMS test, we show that the on-chip decoupling capacitor enhances the EM noise immunity.

• 한국해양공학회지
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• 제13권3B호
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• pp.38-46
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• 1999

Increasing stringent emissions legislation and requirement of more effective energy used for diesel engine demand the fine control of the fuel injection system. Recently, the electromagnetic fuel injection control system for diesel engine is tried to realize the optimum diesel combustion by the feel back sensing as optical signal of combustion flame. The photo detectors were made for the feed back signal of electromagnetic fuel injection control for small DI diesel engine. Their abilities to detect defining combustion events were examined. By evaluating test results, it was shown that the wider acceptable optical range design of optical probe window face, and selection of installation position and installation method of detector were important point for improving sensing ability. The detector was shown to detect start and end of diffused combustion and maximum point of flame intensity impossible for pressure sensor, and also shown that the maximum point of flame intensity was 75% of accumulated heat release point within the experimental conditions.

• 대한기계학회논문집B
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• 제22권9호
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• pp.1255-1266
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• 1998

Effects of a length-to-diameter ratio, L/D, on the three-dimensional flow and aerodynamic loss within an injection hole, which is normally oriented to the mainflow, have been investigated by using a straight five-hole probe. The length-to-diameter ratio of the injection hole is varied to be 0.5 and 2.0 for blowing ratios of 0.5, 1.0 and 2.0. Regardless of the blowing ratio, flows within the hole and at the jet exit are strongly affected by the length-to-diameter ratio. In the case of L/D=0.5, the inside flow is considerably influenced by the mainflow, and the exit flow variation is found to be the greatest. The aerodynamic loss in this case is usually attributed to jet -mainflow interactions. In the case of L/D=2.0, the flow separation and reattachment in the inlet region are completely separated from the complicated exit flow, and the aerodynamic-loss production is mainly due to the inlet flow separation.

• JSTS:Journal of Semiconductor Technology and Science
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• 제1권1호
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• pp.15-19
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• 2001

Current leakage is the major failure mode of semiconductor device characteristic failures. Conventionally, failures such as short circuit breaks and gate breakdowns have been analyzed and the detected causes have been reflected in the fabrication process. By using a wafer-level emission-leakage failure analysis method (in-line QC), we analyzed leakage mode failure, which is the major failure detected during the probe inspection process for LSIs, typically DRAMs and CMOS logic LSIs. We have thus developed a new technique that copes with the critical structural failures and random failures that directly affect probe yields.

• Nuclear Medicine and Molecular Imaging
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• 제42권6호
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• pp.451-455
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• 2008

목적 : 전초림프절 스캔과 전초림프철 생검은 유방암 환자에서 액와림프절 전이를 인지하기 위한 표준화된 방법으로 사용되게 되었지만, 표준화된 방사성의약품은 마련되어 있지 않다. 액와림프절 전이를 인지하기 위한 전초림프절 검사에 있어서 본 연구에서는 Tc-99m Tin-colloid와 Tc-99m Phytate의 결과를 비교하여 보았다. 대상 및 방법: 본 연구에서는 2001년에서 2008년까지 유방암으로 수술을 시행했던 381명의 환자를 대상으로 하였다. 349명의 환자는 Tc-99m Tin-colloid (37-185MBq) 0.8ml를 유륜하로 주사하였다. 33명의 환자는 Tc-99m Phytate (37-185 MBq) 0.8 ml를 유륜하로 주사하였다. 앉은 자세에서 림프신티그라피가 시행되었고, 수술 중에 감마프로브로 전초림프절을 발견하였다. 결과: Tc-99m Tin-celloid로 검사를 시행한 전체 349명의 환자 중에서 312명(89.4%)이 림프신티그라피에 의해 전초림프절이 발견되었고, 304명(87.1%)이 감마프로브에 의해 전초림프절이 발견되었다. 전날검사를 시행한 전체 33명의 환자 중에서 32명(97.0%)이 림프신티그라피에 의해 전초림프절이 발견되었고 33명(100%)이 감마프로브에 의해 전초림프절이 발견되었다. Tc-99m Phytate에 의한 림프신티그라피와 감마프로브에 의한 전초림프절 발견율은 Tc-99m Tin-celloid와 비교하여 통계학적으로 유의하게 높았다 (p<0.05, P<0.05). 결론: 유방암 환자에서 전초림프절을 발견하는데 있어 Tc-99m Phytate가 Tc-99m Tin-colloid보다 더 좋은 선택일 것이다.

• 대한기계학회논문집B
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• 제21권9호
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• pp.1185-1197
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• 1997

Three-dimensional flow within a film-cooling hole, which is normally oriented to the main flow, has been measured by using a straight five-hole probe for the blowing ratios of 1.0 and 2.0. The length-to-diameter ratio of the injection hole is fixed to be 1.0 throughout the whole experiments. The result shows that the secondary flow within the hole is strongly affected by the main flow and flow separation at the hole inlet. The higher blowing ratio provides less influence of the main flow on the injectant flow. The three-dimensional flow at the hole exit is considerably altered due to the strong interaction between the injectant and main flow. The aerodynamic loss produced inside the injection hole is mainly attributed to the inlet flow separation.