• Proceedings of the Korean Magnestics Society Conference
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• 2007.05a
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• pp.306.2-306.2
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• 2007

• International Journal of Vascular Biomedical Engineering
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• v.4 no.2
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• pp.25-30
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• 2006

We intended to measure the IT, MT, and the IMT of carotid artery separately and tried to analyze the clinical significance. Two hundred and fifty consecutive patients (125 males, 125 females) underwent carotid artery scanning using high-resolution ultrasound. The images were off-line analyzed using B-mode ultrasound image processing, devised in our research. We measured the IT, MT, and IMT semi-automatically at the far wall of designated 1cm length of the right common carotid and calculated the average values over the 200 points. The IT (p < 0.05), MT (p < 0.05) as well as IMT (p < 0.01) of patients with atherosclerotic disease were significantly thicker than that of the patients without atherosclerotic disease. Patients with hypertension showed significantly thicker IT (p < 0.05), MT (p < 0.01), and IMT (p < 0.01) than that of the patients without hypertension. However, only IT was thicker in patients with smoking (p < 0.05) than that of the patients without smoking. Smoking was associated only with intima while hypertension was associated with the all three layer's thickness. This result suggests the atherosclerotic process can be different by cardiovascular risk factors.

• The Journal of Korea Robotics Society
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• v.5 no.1
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• pp.32-40
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• 2010

This paper proposes the technique of estimating the pipe thickness using the measured group velocity. To measure the group velocity from the accelerometer data in the frequency domain, Wigner-Ville distribution is utilized, which interprets the waveform of the shock wave. Using this measured group velocity, this paper proposes the technique to estimate the thickness of pipes with the impact on the pipe. The group velocity is estimated by the modeling correlation between the group velocity and the thickness of the pipe based on the propagation velocities. The correlation model between thickness and group velocity has been proved through the real experiments. The measured group velocity in the frequency-domain is the maximum at the center frequency of the bending waves in the modeling of the group velocity. In addition to these, a smoothing technique for analyzing lamb wave Wigner-Ville distribution has been introduced to improve the reliability of the data acquisition.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1907-1910
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• 2005

Coating thickness is an important variable that plays a role in product quality, process control, and cost control. Measurement of film thickness can be done with many different instruments. In this paper, we introduce the new eddy current system for measure the thickness of nonconductive coatings on nonferrous metal substrates. The experimental results are shown that the proposed system is able to measure thickness of plastic film coating on aluminum plates in the range of 0 to 1000 microns with satisfy sensitivities, linearity, resolution and stability of the system.

• Journal of Ceramic Processing Research
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• v.13 no.spc2
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• pp.403-406
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• 2012

Effect of thickness on ZnO properties including the compositional ratio and crystallinity has been systematically investigated using a variety of characterization tools of x-ray diffraction, field emission scanning electron microscopy, x-ray fluorescence and x-ray photoelectron spectroscopy. Interestingly, it was observed that ZnO films below 80 nm in thickness were in oxygen deficiency, while the oxygen ratio was increased in the films above the thickness, although the compositional ratio of ZnO film was not linearly varied with increasing film thickness. Also, ZnO crystallinity, which is characterized by (002) diffraction pattern, was clearly improved with increasing film thickness. The properties of ZnO film with different sputtering time and the nature of direct current reactive sputtering process were discussed in terms of compositional ratio, especially oxygen ratio in ZnO film.

• Tribology and Lubricants
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• v.27 no.5
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• pp.256-263
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• 2011

Bearings of marine engines are operated under severe conditions because of dynamic load and low sliding speed. This paper deals with lubrication analysis of a crank pin bearing for a marine diesel engine. Journal center locus and oil film thickness are compared of crank pin bearing. In the past researches, journal bearings have been studied only about the surface of bearing. In addition to this conventional research, this paper analyzes the effect of roundness error of a journal and a bearing on the minimum film thickness. Numerical analysis has been studied by using Reynolds equation and also Half-Sommerfeld condition is applied as boundary condition. Futhermore, this study investigates the effect of roundness error change on the minimum film thickness. The results demonstrate that the bigger amplitude of roundness error yields, the lower minimum oil film thickness is. In comparison to previous research considered a journal and a bearing individually, the results considering a journal and a bearing together show that amplitude of roundness error of journal has very little effect on the minimum oil film thickness.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.12
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• pp.2014-2018
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• 2016

Transparent, conductive electrode films, showing the particular characteristics of good conductivity and high transparency, are of considerable research interest because of their potential for use in opto-electronic applications, such as smart window, photovoltaic cells and flat panel displays. Multilayer transparent electrodes, having a much lower electrical resistance than widely-used transparent conducting oxide electrodes, were prepared by using RF/DC magnetron sputtering system. The multilayer structure consisted of three layers, [NiInZnO(NIZO)/Ag/NIZO]. The optical and electrical properties of the multilayered NIZO/Ag/NIZO structure were investigated in relation to the thickness of each layer. The optical and electrical characteristics of multilayer structures have been investigated as a function of the Ag and NIZO film thickness. High-quality transparent conductive films have been obtained, with sheet resistance of $9.8{\Omega}/sq$ for Ag film thickness of 8 nm. Also the multilayer films of inserted Ag 8 nm thickness showed a high optical transmittance above 93% in the visible range. The electrical and optical properties of the new multilayer films were mainly dependent on the thickness of Ag insertion layer.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.8
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• pp.2157-2163
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• 2009

The oxygen permeability of a soft contact lens is an important parameter for determining corneal health when considering the physiological response of the eye. The aim of this study is to evaluate the oxygen permeability of soft contact lenses based on thickness, using the polarographic method. The thickness of lens was measured using contact and non-contact method. To assess accuracy and reliability, the Bland-Altman plot was used. The reliability was high for the oxygen permeability based on center thickness measured by contact method, whereas the accuracy was high for the oxygen permeability based on center thickness measured by non-contact method. These results indicate that the permeability characteristics were variable according to the measurement and criteria of thickness of soft contact lenses and the measurement of soft contact lenses by non-contact method was more reasonable. Thus, contact lens practitioners should consider some basic differences between methodologies when interpreting or quoting oxygen performance data.

• Physical Therapy Rehabilitation Science
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• v.3 no.2
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• pp.93-100
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• 2014

Objective: The purpose of this study was to determine the effect of the abdominal bracing (AB) and abdominal bracing combined with ankle dorsiflexion (ABDF) on abdominal muscle thickness and strength in patients with chronic low back pain (LBP). Design: Two group pretest posttest design. Methods: Sixteen subjects were divided randomly into two group: ABDF group (n=8), and alone AB group (n=8). The ABDF group practiced AB exercise with additional ankle dorsiflexion. AB group practiced only AB exercises. Subjects in both groups received ABDF exercise and AB exercise for 40 min per day, three days per week during a period of three weeks, respectively. All the subjects were evaluated for abdominal muscle thickness and strength before and after intervention using ultrasonography and MedX machine. Results: The external oblique (EO), internal oblique, transverse abdominis (TrA) muscle thickness and the strength produced at $48^{\circ}$, $60^{\circ}$, $72^{\circ}$ showed a significant increase in the ABDF group after intervention, with a more significant improvement in EO and TrA muscle thickness in the ABDF group compared with the AB group (p<0.05). Also, the strength at $48^{\circ}$ strength showed a significant improvement in the ABDF group than the AB group (p<0.05). Conclusions: The study results showed that abdominal muscle contraction exercises with AD in patients with LBP had an influence on abdominal muscle thickness and strength. Therefore, these findings suggest that ABDF may be useful approach for enhancement of abdominal muscle thickness and strength in patients with chronic low back pain.

• Journal of Korean Physical Therapy Science
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• v.29 no.1
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• pp.64-72
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• 2022

Background: The purpose of this study is to investigate the effect of wall squat exercise according to the difference in the support surface on the thickness change of external oblique, internal oblique and transverse abdominalis of the trunk muscles and the change in distance of center of pressure when the eyes are opened and closed. Design: Randomized controlled trial. Methods: The subjects were 26 healthy adults, 18 males and 8 females. The composition of each group using the single-blind method was 13 people in the unstable side wall squat exercise group and 13 people in the stable side wall squat exercise group. Experimental measurements were divided into before, 3 weeks, and 6 weeks after the experiment, and changes in muscle thickness and balance were confirmed. Muscle thickness was measured using ultrasinic, and static balance change was measured using Bio-rescue. Results: There were significant differences in the thickness changes of external oblique, internal oblique and transverse abdominalis according to the wall squat exercise method by period and in the interaction between the period and the group (p<0.05). As a result of the post-hoc analysis, there was a significant difference in the change between the two groups in external oblique muscle after 6 weeks. And there was a significant difference in the distance of the pressure center between eyes open and closed eyes (p<0.05). Conclusion: In terms of instability, wall squat exercise was positive for changes in trunk muscle thickness. It suggests the possibility of using it for trunk muscle strengthening training in the future.