• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2009.10a
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• pp.229-230
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• 2009

본 연구에서는 플라즈마 기본 변수인 전자밀도, 전자온도, 그리고 이온 유량을 제어하는 조정기를 설계하였다. 플라즈마 증착장비를 이용하여 상온에서 SiN 박막을 증착하는 과정에서 in-situ 센서인 Wise Probe를 이용하여 데이터를 수집하였다. 수집된 데이터를 이용하여 플라즈마 확인 (Identification) 모델을 개발하고, 이를 이용하여 Linear Quadratic Regulator를 설계하였다. Noise와 Disturbance에 대한 응답특성을 고찰하였으며, 설계된 Regulator는 비교적 안정된 반응을 보였다.

• Journal of the Semiconductor & Display Technology
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• v.15 no.4
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• pp.33-35
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• 2016

In this study, a new plasma source was used in the ALD process. Line type plasma sources were analyzed by electric and magnetic field simulation. And the results were compared with plasma density and electron temperature measurement results. As a result, the results of the computer simulation and the diagnosis results of plasma density and electron temperature showed similar tendency. At this time, the plasma uniformity is 95.6 %. $Al_2O_3$ thin film was coated on 6 inch Si-wafer, using this plasma source. The uniformity of the thin film was more than 98% and the thin film growth rate was 0.13 nm/cycle.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.215.1-215.1
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• 2016

플라즈마는 반도체, 디스플레이, 태양전지 등 다양한 산업 분야에 이용된다. 플라즈마 공정 시 수율 향상을 위해 플라즈마를 진단하는 기술이 필요한데, 대표적으로 전자온도가 있다. 반도체 공정의 낮은 압력과 높은 밀도의 플라즈마에서 전자온도는 1~10 eV 정도인데, 0.5 eV정도의 아주 적은 차이로도 공정 결과에 큰 영향을 미친다. 플라즈마의 전자온도를 측정하는 방법은 전기적 탐침 방법인 랑뮤어 탐침(Langmuir Probe)과 와이즈 프로브(Wise Probe)를 이용한 방법, 그리고 광학적 방법인 방출분광법(OES : Optical Emission Spectroscopy)이 있다. 전기적 탐침 방법은 직접 플라즈마 내부에 탐침을 넣기 때문에 불활성 기체를 사용한 공정에서는 잘 작동하지만 건식식각이나 증착에 사용할 경우 탐침의 오염으로 인한 오동작, 공정 시 생성된 샘플에 영향을 줄 수 있다는 단점이 있다. 반면에 방출분광법은 광학적 진단으로, 플라즈마를 사용하는 공정 진행 중에 외부에 광학계를 설치하여 플라즈마에서 발생하는 빛을 광학적으로 분석하기 때문에 공정에 영향을 미치지 않고, 공정 장비에 적용이 쉬운 장점을 가지고 있다. 본 연구에서는 RF Power를 인가한 유도결합플라즈마(ICP : Inductively Coupled Plasma) 공정에서 아르곤 가스와 산소 혼합가스 분압과 인가전압을 변화시켜 플라즈마 방출광 세기 변화에 따른 전자온도를 측정하였다. 전자온도 측정에는 전기적 방법인 랑뮤어 탐침, 와이즈 프로브를 이용한 방법과 광학적 방법인 방출분광법을 사용하여 측정하였으며 이를 비교 분석하였다.

• Journal of Chest Surgery
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• v.24 no.4
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• pp.345-351
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• 1991

The myocardial temperature was monitored in 19 patients of open heart surgery using the Shiley myocardial temperature probe in Department of Thoracic and Cardiovascular Surgery, Yeungnam University Hospital. The myocardial temperature were measured time-wise: initial and 15 minutes following the infusion of the cardioplegic solution into the aortic root and upon reinfusion, which is 30 minutes apart from the initial. The measurements were made in the anterior wall of the right ventricle, the posterior wall of the left ventricle and the interventricular septum. Immediately after initial infusion, the temperature of the right ventricle[10.7 $\pm$4.3oC] was the lowest and that of the left ventricle[12.9$\pm$3.9 oC] the highest in the mean values among all 19 patients. However, no significant differences were noted among the different regions. At 15 minutes after infusion, the lowest temperature was in the right ventricle[17.5$\pm$5.1 oC], followed by interventricular septum[17.9$\pm$2.9 oC], and left ventricle[21.4$\pm$2.5 oC]. At 30 minutes after infusion, the lowest temperature was measured in the interventricular septum[13.6$\pm$2.7 oC ], followed by right ventricle[13.8$\pm$4.0 oC] and left ventricle[14.5$\pm$4.5 oC ]. Evaluating changes of myocardial temperature according to postinfusion time, the temperature at 15 minutes after infusion showed significant increase as compared with that immediately after the infusion in all three regions[p<0.05] and the temperature at 30 minutes after infusion showed significant decrease as compared with that at 15 minutes after the infusion in the left ventricle and the interventricular septum[p<0.05]. The left ventricle was rewarmed most rapidly and its temperature the highest in the mean values, Accordingly, the maintenance of optimal hypothermia of the left ventricle indicated a very careful factor in myocardial protection.

• Journal of the Korean earth science society
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• v.25 no.7
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• pp.532-544
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• 2004

The purpose of this study is to analyze the concept concerned with Earth's rotation as passed by tenth graders whose interest in earth's rotation and learning styles were varied. To examine student's interest in the Earth's rotation, 4students (visual-verbal learning style student with much interest, visual learning style student with much interest, visual learning style student with little interest, and verbal learning style student with little interest) were chosen for study. Personal interview was used for this study. To probe students' conception in varied ways, they were allowed to make gesture and draw pictures through data collection process, except for interviews. And the data were analyzed one by one. The result of this study were as follows: First, the student with much interest was faster to answer the questions about Earth's rotation than the one with little interest. Also he comprehended better and was able to explain reasons coherently. Second, there was little difference according to student's learning style. Third, one of the repeated misconception was direction. For thinking that is the right side is the east side, students have misconception that the sun goes from right to left and stars in north sky move clock-wise.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.2
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• pp.172-180
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• 2007

Among the nuclear medicine imaging methods available today, $H_2^{15}O-PET$ is most widely used by cognitive neuroscientists to examine regional brain function via the measurement of regional cerebral blood flow (rCBF). The short half-life of the radioactively labeled probe, $^{15}O$, often allows repeated measures from the same subjects in many different task conditions. $H_2^{15}O-$ PET, however, has technical limitations relative to other methods of functional neuroimaging, e.g., fMRI, including relatively poor time and spatial resolutions, and, frequently, insufficient statistical power for analysis of individual subjects. However, recent technical developments, such as the 3-D acquisition method provide relatively good image quality with a smaller radioactive dosage, which in turn results in more PET scans from each individual, thus providing sufficient statistical power for the analysis of individual subject's data. Furthermore, the noise free scanner environment $H_2^{15}O$ PET, along with discrete acquisition of data for each task condition, are important advantages of PET over other functional imaging methods regarding studying state-dependent changes in brain activity. This review presents both the limitations and advantages of $^{15}O-PET$, and outlines the design of efficient PET protocols, using examples of recent PET studies both in the normal healthy population, and in the clinical population.