• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제18권2호
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• pp.108-114
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• 2015

Purpose: The aim of this study is to evaluate the relationship between abdominal subcutaneous fat thickness measured by ultrasonography (US) and serum lipid profile and liver transaminases in obese children. Methods: One hundred and sixty-six children diagnosed with obesity from May 2001 to December 2013 were included in this study. Data on serum lipid profile and liver transaminases were collected from clinical records. Abdominal subcutaneous fat thickness and grade of hepatic steatosis were evaluated by US. Results: Of the 166 children, 107 were diagnosed with hepatic steatosis by US, 46 with grade I, 56 with grade II, and five children with grade III. According to the grade of hepatic steasosis, the average values of midline abdominal subcutaneous fat thickness and right flank abdominal subcutaneous fat thickness measured $2.9{\pm}0.8cm$ and $1.9{\pm}0.7cm$ in the normal group, $3.3{\pm}0.8cm$ and $2.0{\pm}0.7cm$ in grade I, $3.8{\pm}0.8cm$ and $2.3{\pm}0.8cm$ in grade II, and $4.1{\pm}0.8cm$ and $2.8{\pm}1.4cm$ in grade III, respectively. Abdominal subcutaneous fat thickness correlated with grade of hepatic steatosis (p<0.01). In addition, abdominal subcutaneous fat thickness correlated with concentration of serum lipids and liver transaminases in the age group of 12-14 years (p<0.01). Conclusion: Abdominal subcutaneous fat thickness measured by US can be used as a reliable predictor of possible hyperlipidemia and steatohepatitis in children, especially during the adolescent stage.

• 한국진공학회지
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• 제5권4호
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• pp.327-332
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• 1996

Tungsten(W) polycide gate 구조에서 $WSi_x$의 두께가 증가하면 열처리 공정 후 Gate oxide의 두께가 증가하며, 전기적 신뢰도가 열화 되는 현상이 발생한다. 이러한 특성 열화를 일으키는 지배적인 요인은 $WSi_x$ 증착 공정 중 유입되어 후속 열 공정에 의하여 gate oxide로 환산되는 fluorine인 것으로 밝혀졌다. 이러한 현상을 규명하기 위하여 fluorine ion implantation된 poly Si과의 특성을 비교하였으며, SIMS 및 단면 TEM을 이용한 미세 구조 연구를 실시하였다. 그러나 $WSi_x$의 두께가 600$\AA$ 이상부터는이러한 특성 열화가 포화되는 현상이 관찰되었다. 600$\AA$ 이상의 $WSi_x$ 두께에서는 미세 구조가 표면이 거칠고, porous한 phase로 구성된 상부 구조와 비교적 dense하고, 매끈한 계면 상태를 갖는 하부 구조로 이루어졌으며, porous한 표면 부위는 후속 열공정 중 oxygen-rich한 phase로 변하여 fluorine을 포획하여 oxide로의 확산을 억제하여 특성 열화가 포화되는 것으로 해석되었다.

• International Journal of Concrete Structures and Materials
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• 제10권sup3호
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• pp.19-31
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• 2016

The objective of this paper is to investigate the effect of thickness and moisture on temperature distributions of reinforced concrete walls under fire conditions. Toward this goal, the first three wall specimens having different thicknesses are heated for 2 h according to ISO standard heating curve and the temperature distribution through the wall thickness is measured. Since the thermal behavior of the tested walls is influenced by thickness, as well as moisture content, three additional walls are prepared and preheated to reduce moisture content and then tested under fire exposure. The experimental results clearly show the temperatures measured close to the fire exposed surface of the thickest wall with 250 mm thickness is the highest in the temperatures measured at the same location of the thinner wall with 150 mm thickness because of the moisture clog that is formed inside the wall with 250 mm of thickness. This prevents heat being transferred to the opposite side of the heated surface. This is also confirmed by the thermal behavior of the preheated walls, showing that the temperature is well distributed in the preheated walls as compared to that in non-preheated walls. Finite element models including moisture clog zone are generated to simulate fire tests with consideration of moisture clog effect. The temperature distributions of the models predicted from the transient heat analyses are compared with experimental results and show good agreements. In addition, parametric studies are performed with various moisture contents in order to investigate effect of moisture contents on the thermal behaviors of the concrete walls.

• 한국전기전자재료학회논문지
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• 제24권7호
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• pp.568-573
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• 2011

AZO (Al doped ZnO) thin films were deposited on the quartz substrates with thickness variation from 25 to 300 nm by using PLD (pulsed laser deposition). XRD (x-ray diffractometer), SPM (scanning probe microscopy), Hall effect measurement and uv-visible spectrophotometer were employed to investigate the structural, morphological, electrical and optical properties of the thin films. XRD results demonstrated that films were preferrentially oriented along the c-axis and crystallinity of film was improved with increase of film thickness. As for the surface morphologies, the mean diameter and root mean square of grains were increased as the film thickness was increased. When the film thickness was 200 nm, the lowest resistivity of $4.25{\times}10^{-4}\;{\Omega}cm$ obtained with carrier concentration of $6.84{\times}10^{20}\;cm^{-3}$ and mobility of $21.4\;cm^2/V{\cdot}S$. All samples showed more than 80% of transmittance in the visible range. Upon these results, it is found that the samples thickness can affect their structural, morphological, optical and electrical properties. This study suggests that the resistivity can be improved by controlling film thickness.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2004년도 학술대회지
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• pp.283-288
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• 2004

The measurement of ultra low aspect ratio fluid film thickness is very crucial technique both for the verification of lubrication media characteristics and for the clearance design in many precision components such as MEMS, precision bearings and other slideways. Many technologies are applied to the measurement of ultra low aspect ratio fluid film thickness (i.e. elastohydrodynamic lubrication film thickness). In particular, in-situ optical interferometric method has many advantages in making the actual contact behaviors realized with the experimental apparatus. This measurement method also does the monitoring of the surface defects and fractures happening during the contact behavior, which are delicately influenced by the surface conditions such as load, velocity, lubricant media as well as surface roughness. Careful selection of incident lights greatly enhances the fringe resolutions up to $\~1.0$ nanometer scale with digital image processing technology. In this work, it is found that coaxial aligning trichromatic incident light filtering system developed by the author can provide much finer resolution of ultra low aspect ratio fluid film thickness than monochromatic or dichromatic incident lights, because it has much more spectrums of color components to be discriminated according the variations of film thickness. For the measured interferometric images of ultra low aspect ratio fluid film thickness it is shown how the film thickness is finely digitalized and measured in nanometer scale with digital image processing technology and space layer method. The developed measurement system can make it possible to visualize the contact deformations and possible fractures of contacting surface under the repeated loading condition.

• 대한방사선치료학회지
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• 제8권1호
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• pp.55-61
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• 1996

A radiation beam incident on irregular or sloping surface produces an inhomogeneity of absorbed dose. The use of a tissue compensator can partially correct this dose inhomogeneity. The tissue compensator should be made based on experimentally measured thickness ratio. The thickness ratio depends on beam energy, distance from the tissue compensator to the surface of patient, field size, treatment depth, tissue deficit and other factors. In this study, the thickness ratio was measured for various field size of $5cm{\times}5cm,\;10cm{\times}10cm,\;15cm{\times}15cm,\;20cm{\times}20cm$ for 4MV X-ray beams. The distance to the compensator from the X-ray target was fixed, 49cm, and measurement depth was 3, 5, 7, 9 cm. For each measurement depth, the tissue deficit was changed from 0 to(measurement depth-1)cm by 1cm increment. As a result, thickness ratio was decreased according to field size and tissue deficit was increased. Use of a representative thickness ratio for tissue compensator, there was $10\%$ difference of absorbed dose but use of a experimentally measured thickness ratio for tissue compensator, there was $2\%$ difference of absorbed dose. Therefore, it can be concluded that the tissue compensator made by experimentally measured thickness ratio can produce good distribution with acceptable inhomogeneity and such tissue compensator can be effectively applied to clinical radiotherapy.

• 한국전문물리치료학회지
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• 제17권4호
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• pp.49-54
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• 2010

The reliability of the thickness measurement of the lumbar multifidus (LMD using real-time ultrasonography (US) was determined in only the superficial fiber of the lumbar multifidus (SM). However, previous studies have not examined the reliability of the deep fiber of the LM (DM). The purpose of this study was to determine the intrarater and the interrater reliability of the thickness measurements of DM using US. Eleven heathy males participated in the study. The thickness of the DM was measured with an US in the prone position. Reliability was examined using intraclass correlation coefficients (ICC), standard error of the measurement (SEM), and the Bland and Altman plot. ICC(3,1) was used to calculate the interrater reliability of the thickness measurement of DM using the values from both the first and second test sessions. Additionally, ICC(3,1) was used to calculate the intrarater reliability of the measurements over two days using the measurements obtained in test session 1 and lest session 2. The results of this study were as follows: 1) the ICC(3,1) value for interrater reliability was .94 in the first test session, and .93 in the second test session. 2) the ICC(3,1) values for intrarater reliability of the measurements over two days was .90 in both the first examiner and the second examiner. The interrater reliability and interrater reliability of the DM measurements, obtained via the US protocol used in this research was excellent. Therefore, we conclude that the thickness measurement of the DM obtaioned from the US protocol used in this research would be useful for clinician assessment of the thickness of the DM.

• 대한간호학회지
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• 제40권2호
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• pp.247-254
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• 2010

Purpose: To study the thickness of gluteal subcutaneous fat (SCF) and propose an adequate length for needle for gluteal intramuscular injections based on computed tomography (CT) measurements. Methods: The thickness of gluteal SCF were measured and studied for 568 patients who visited a tertiary hospital in Seoul, Korea between January 2007 and February 2009 for routine health screening and who had abdominopelvic CT. Results: The average thickness of gluteal SCF was $15.92{\pm}4.08mm$ in males and $24.90{\pm}5.47mm$ in females. The thickness of gluteal SCF differed significantly according to gender. The gluteal SCF thickness was greater than 20.4 mm for 54 (12.3%) of the 440 male patients and 99 (77.3%) of the 128 female patients. Conclusion: The most common syringe needle used for gluteal intramuscular injections in Korea is a 23 G, 25.4 mm-needle. The SCF thickness must be less than 20.4 mm in order to reach the dorsogluteal muscles to a depth of at least 5 mm if this 25.4 mm needle is used. In many patients, especially in female patients, the 25.4 mm needles will result in improper intramuscular injections with the injection being into the SCF. Therefore an appropriate needle should be selected by considering the gender and SCF thickness of patients receiving gluteal intramuscular injections.

• 전자공학회논문지
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• 제51권6호
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• pp.190-197
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• 2014

본 논문에서는 초음파를 이용하여 재질의 두께를 실측하고 렌더링하는 방법을 제안한다. 두께는 광학특성과 함께 반사율과 투과율을 결정하는데 중요한 요소로서 물체를 더욱 사실적으로 표현하는데 영향을 준다. 지금까지의 연구는 두께를 추정하여 렌더링에 사용해왔다. 제안된 방법은 육안으로 두께를 측정할 수 없는 물체의 두께를 초음파를 이용하여 측정하여 렌더링하는 처음 시도된 방법이다. 이를 위해 기준시편의 음속을 측정하고, 같은 성질을 갖는 다른 물체들의 두께를 측정한다. 측정된 물체의 특성들은 최종적으로 렌더링되고, 영상 분석 모델을 통해 결과를 확인하며, 이를 통해 렌더링에서 두께의 중요성을 확인할 수 있다.

• 대한치과기공학회지
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• 제32권4호
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• pp.327-335
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• 2010

Purpose: The purpose of this study was to investigate the correlation between zirconia core thickness and color tone blocking of discolored tooth and metal post. Methods: For this study, we made 20-porcelain sample and 4-metal sample( liechtenstein IPS e.max) bonded to zirconia core of different thickness with cement(Relyx ARC-3M USA)for produce discolored. We measured the color-spectral characteristics, using Shadepilot equipment(Degudent USA).We measured it with Shadepilot equipment set by automated average mode in 3 times And applied the average value obtained from 2 times of measurement in the middle of each sample. Results: As a result of analysing color-spectral characteristics on zirconia core sample, Depending on the thickness of zirconia core, the value of brightness(${\Delta}L*$:color-spectral characteristic) was increased within limited range, value of ${\Delta}a*$, ${\Delta}b*$ was decrease. Conclusion: Consequently, we obtained the following results: Changes of sample color were observed depending on the thickness of zirconia, but the range of change did not exceed the scope range of shade guide. The case of metal posts, shade guide color D2 were observed in 0.5mm of zirconia core thickness. As a result, in case of porcelain, increasing the zirconia thickness of 0.3mm or more is unnecessary for color blocking effect, in case of metal post, considering the discolored tooth, thickness of zirconia with at least 0.5mm or more is recommended.