• 한국정보통신학회논문지
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• 제22권1호
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• pp.117-124
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• 2018

박막 두께가 다른 무접합 비정질 InGaZnO 막막 트랜지스터를 제작하고 박막 두께, 동작 온도 및 빛의 세기에 따른 소자의 성능 변수를 추출하고 게이트 산화층 항복전압을 분석하였다. 박막의 두께가 클수록 소자의 성능이 우수하나 드레인 전류의 증가로 게이트 산화층 항복전압은 감소하였다. 고온에서도 소자의 성능은 개선되었으나 게이트 산화층 항복 전압은 감소하였다. 빛의 세기가 증가할수록 광자에 의해 생성된 전자로 드레인 전류는 증가 하였으나 역시 게이트 산화층 항복전압은 감소하였다. 박의 두께가 클수록, 고온일수록, 빛의 세기가 강할수록 채널의 전자수가 증가하여 산화층으로 많이 주입되었기 때문이다. 무접합 a-IGZO 트랜지스터를 BEOL 트랜지스터로 사용하기 위해서는 박막 두께 및 동작 온도를 고려해서 산화층 두께를 설정해야 됨을 알 수 있었다.

• Journal of Korean Biological Nursing Science
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• 제17권1호
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• pp.44-49
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• 2015

Purpose: This research was aimed at evaluating the differences in depression by skinfold thickness, and the relationship between two variables. Methods: Research design was a non-experimental descriptive survey. Using a caliper, we measured skinfold thickness on the triceps, and then on the suprailiac, and the mid-thigh. Depression was evaluated using the Geriatric Depression Scale-Short Form (GDS-SF). Data were collected for one month from Sept 1st to 30th, 2011. There were 52 subjects, 25 of which were from elderly welfare centers and 27 were hospitalized. Results: Subjects were an average age of $76.4{\pm}4.45$, and the incidence rate of depression (${\geq}6$) was 36.5% and those who had a sum of 3 skinfolds over 62 mm were 22.7%. The GDS-SF was significantly different in only the suprailiac skinfold thickness (F=7.25, p<.05). Conclusion: Findings indicate that depression is different based on suprailiac thickness in older adult women at elderly welfare centers and those who were hospitalized in an medical ward. It suggests that the suprailiac skinfold may be an indicator of abdominal obesity when considering depression in elderly women. Further study is needed to evaluate a cutoff score of skinfold thickness in obesity for older adult women.

• Wind and Structures
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• 제8권6호
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• pp.455-467
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• 2005

The effects of upstream velocity profiles on the flow around a low-rise rectangular prism submerged in a turbulent boundary layer have been investigated. Three different boundary layer profiles are generated, which are characterized by boundary layer height, displacement thickness, and momentum thickness. Flow characteristics variations caused by the different layers such as those in turbulent kinetic energy distribution and locations of re-circulating cavities and reattachment points have been precisely measured by using a PIV (Particle Image Velocimetry) technique. Observations were made in a boundary layer wind tunnel at $Re_H$=7900, based on a model height of 40 mm and a free stream velocity of 3 m/s with 15 - 20% turbulence intensity.

• Journal of Electrical Engineering and Technology
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• 제9권6호
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• pp.2079-2088
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• 2014

In this paper, we propose new physically based threshold voltage models for short channel Surrounding Gate Silicon Nanowire Transistor with two different geometries. The model explores the impact of various device parameters like silicon film thickness, film height, film width, gate oxide thickness, and drain bias on the threshold voltage behavior of a cylindrical surrounding gate and rectangular surrounding gate nanowire MOSFET. Threshold voltage roll-off and DIBL characteristics of these devices are also studied. Proposed models are clearly validated by comparing the simulations with the TCAD simulation for a wide range of device geometries.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2000년도 추계학술대회 논문집
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• pp.168-173
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• 2000

The limiting drawing ratio (LDR) under uniform heating of blanks was measured at the various temperature ranges between 25 and $250^{\circ}C$ by using two different blank shapes, square and circular blanks, and six different blank sizes with the drawing ratios(DR) of 2.4 to 2.9. The galvannealed steel sheet (SCP3CM 60/60) of 0.7mm thickness was used. The LDR at warm forming condition reached 1.2 times of that at room temperature, and the maximum drawing depth reached 1.9 times. The higher temperature was adopted, the more stable and uniform thickness strain distribution was observed.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 1995년도 추계 학술대회논문집
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• pp.241-245
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• 1995

This paper presents the studies on the variation of shape and thickness of a normal shock wave with Mach number and density by using the most useful numerical technique in rarefied gas regime, DSMC(Direct Simulation Monte Carlo). Calculations are peformed for the three different Mach numbers and for one Mach number with different densities. From the obtained results, we find that the shock thickness is decreasing with increasing Mach number, and there are much variations in thickness and shape with decreasing density. Also, there is a noticeable overshoot of the translational temperature near the shock center in the case of a large Mach number.

• Steel and Composite Structures
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• 제24권5호
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• pp.537-548
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• 2017

In this paper presents bending characteristic of single wall carbon nanotube reinforced functionally graded composite (SWCNTRC-FG) plates. The finite element implementation of bending analysis of laminated composite plate via well-established higher order shear deformation theory (HSDT). A seven degree of freedom and $C^0$ continuity finite element model using eight noded isoperimetric elements is developed for precise computation of deflection and stresses of SWCNTRC plate subjected to sinusoidal transverse load. The finite element implementation is carried out through a finite element code developed in MATLAB. The results obtained by present approach are compared with the results available in the literatures. The effective material properties of the laminated SWCNTRC plate are used by Mori-Tanaka method. Numerical results have been obtained with different parameters, width-to-thickness ratio (a/h), stress distribution profile along thickness direction, different SWCNTRC-FG plate, boundary condition, through the thickness (z/h) ratio, volume fraction of SWCNT.

• 소성∙가공
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• 제11권5호
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• pp.423-429
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• 2002

The limiting drawing ratio (LDR) under uniform heating of blanks was measured at the various temperature ranges between 25 and 25$0^{\circ}C$ by using two different blank shapes, square and circular blanks, and six different blank sizes with the drawing ratios(DR) of 2.4 to 2.9. The galvannealed steel sheet (SCP3CM 60/60) of 0.7mm thickness were used. The LDR at warm forming condition reached 1.2 times of that at room temperature, and the maximum drawing depth reached 1.9 times. The higher temperature was adopted, the more stable and uniform thickness strain distribution was observed. Some cases of the experimental results were compared with the analitical results using the commercial finite element method (FEM) code.

• 열처리공학회지
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• 제24권1호
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• pp.16-22
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• 2011

Al-Co/AlN-Co multilayer films with different layer thicknesses were prepared by using a two-facing target type D.C sputtering (TFTS) system. The deposited films were annealed isothermally at different temperatures and their microstructure, magnetic properties and resistivity were investigated. The magnetization of as-deposited films is very small irrespective of layer thickness. It was found that annealing conditions and layer thickness ratio (LTR) of Al-Co to AlN-Co can control the microstructure as well as the physical properties of the prepared films. The resistivity and magnetization increase and the coercivity decreases with decreasing LTR. High resistivity and sufficient magnetization were obtained for the films with LTR = 0.35. Films having such considerable magnetization and resistivity will be a potential candidate to be used for a high density recording material.

• 설비공학논문집
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• 제14권6호
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• pp.519-524
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• 2002

An experimental study has been conducted to investigate the effects of surface energy on frost formation. Test samples with two different surfaces are installed in a wind tunnel and exposed to a humid airflow. Dynamic contact angles (DCA) for these surfaces are $23^{\circ}\;and\;88^{\circ}$, respectively. The thickness and the mass of frost layer are measured and used to calculate the frost density while frost formation is visualized simultaneously with their measurements. Results show that frost density increases as time increases at specific test conditions. The air Reynolds number, the airflow humidity and the cold plate temperature are maintained at 12,000, 0.0042 kg/kg and $-21^{\circ}C$, respectively. The surface with a lower DCA shows a higher frost density during two-hour test, but no differences in the frost density have been found after two hours of frost generation. Empirical correlations for thickness, mass and density are assumed to be the functions of the test time and DCA.