• Title/Summary/Keyword: 변이음

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Analysis of the Existing Analytical Solutions for Isotropic Rectangular Thin Elastic Plates with Three Edges Clamped and the Other Free (등방성 직사각형의 3변 고정 1변 자유 얇은 탄성판에 대한 기존 해석해의 분석)

  • Seo, Seung-Nam
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.1A
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    • pp.117-132
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    • 2006
  • The existing analytical solutions for rectangular plates with three edges clamped and the other free are derived based on nondimensional differential equation and their characteristics are analyzed. Since Timoshenko and Woinowsky-Krieger's method (1959) can give solutions for the case limited to the aspect ratio of the plates less than one, this method are proved to be impractical for the bending moment calculation of the plates under consideration. Horii and Moto's method(1968) are modified by adding stabilizing terms to suppress overflow in the matrix computation, from which the series solution with maximum 150 terms can be obtained. By use of the series solution the convergence of computed bending moments is tested. The modified method can be shown to calculate the deflection properties for the plates with wide range of aspect ratios, but the computed x moment at the corner points formed by the free edge and the clamped edges can not satisfy the boundary condition and the cause of problem is discussed in detail.

An Improved Motion/Disparity Vector Prediction for Multi-view Video Coding (다시점 비디오 부호화를 위한 개선된 움직임/변이 벡터 예측)

  • Lim, Sung-Chang;Lee, Yung-Lyul
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.45 no.2
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    • pp.37-48
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    • 2008
  • Generally, a motion vector and a disparity vector represent the motion information of an object in a single-view of camera and the displacement of the same scene between two cameras that located spatially different from each other, respectively. Conventional H.264/AVC does not use the disparity vector in the motion vector prediction because H.264/AVC has been developed for the single-view video. But, multi-view video coding that uses the inter-view prediction structure based on H.264/AVC can make use of the disparity vector instead of the motion vector when the current frame refers to the frame of different view. Therefore, in this paper, we propose an improved motion/disparity vector prediction method that consists of global disparity vector replacement and extended neighboring block prediction. From the experimental results of the proposed method compared with the conventional motion vector prediction of H.264/AVC, we achieved average 1.07% and 1.32% of BD (Bjontegaard delta)-bitrate saving for ${\pm}32$ and ${\pm}64$ of global vector search range, respectively, when the search range of the motion vector prediction is set to ${\pm}16$.

Three-dimensional finite element analysis for influence of marginal bone resorption on stress distribution in internal conical joint type implant fixture (변연골 흡수가 내측연결 임플란트 매식체의 응력분포에 미치는 영향)

  • Yun, Mi-Jung;Yoon, Min-Chul;Eom, Tae-Gwan;Huh, Jung-Bo;Jeong, Chang-Mo
    • The Journal of Korean Academy of Prosthodontics
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    • v.50 no.2
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    • pp.99-105
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    • 2012
  • Purpose: The change of the marginal bone around dental implants have significance not only for the functional maintenance but also for the esthetic success of the implant. The purpose of this study was to investigate the load transfer of internal conical joint type implant according to marginal bone resorption by using the three-dimensional finite element analysis model. Materials and methods: The internal conical joint type system was selected as an experimental model. Finite element models of bone/implant/prosthesis complex were constructed. A load of 300 N was applied vertically beside 3 mm of implant axis. Results: The pattern of stress distribution according to marginal bone resorption was similar. The maximum equivalent stress of implant was increase according to marginal bone resorption and the largest maximum equivalent stress was shown at model of 1 mm marginal bone resorption. Although marginal bone loss more than 1mm was occurred increasing of stress, the width of the stress increase was decreasing. Conclusion: According to these results, the exposure of thin neck portion of internal conical joint type implant is most important factor in stress increasing.

Analysis of Electromagnetic Scattering by a Resistive Strip Grating with Tapered Resistivity on Dielectric Multilayers (다층 유전체위의 변하는 저항율을 가진 저항띠 격자구조에 의한 전자파 산란 해석)

  • Uei-Joong Yoon
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.8 no.5
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    • pp.495-503
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    • 1997
  • In this paper, the E-polarized electromagnetic scattering problems by a resistive strip grating with tapered resistivity on 3 dielectric layers are analyzed to find out the effects for the tapered resistivity of resistive strip and the relative permittivity and thickness of 3 die- lectric layers by applying the Fourier-Galerkin moment methods. The induced surface current density is expanded in a series of Jacobi-polynomial ${P^{(\chi,\beta)}}_p$(.) of the order $\alpha$= 0 and $\beta$=1 as a kind of orthogonal polyomians, and the tapered resistivity assumes to vary linearly from 0 at one edge to finite resistivity at the other edge. The normalized reflected and transmitted powers are obtained by varying the tapered resistivity and the relative permittivity and thickness of dielectric layers. The sharp variation points are observed when the higher order modes are transferred between propagating and evanescent modes, and in general the local minimum positions occur at less grating period for the more relative permittivity of dielectric layers. It should be noted that the patterns of the normalized reflected and transmitted powers for the tapered resistivity are very much different from those of the uniform resistivity and perfectly conducting cases. The proposed method of this paper cna solve the scattering problems for the tapered resistive, uniform resistive, and PEC strip cases.

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Computer-Aided Diagnosis of Liver Cirrhosis using Wave Pattern of Spleen in Abdominal CT Imaging (복부 CT영상에서 비장의 웨이브 패턴을 이용한 간경변의 자동 진단)

  • Seong Won;Cho June-Sik;Noh Seung-Moo;Park Jong-Won
    • Journal of KIISE:Software and Applications
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    • v.32 no.6
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    • pp.532-541
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    • 2005
  • We examined the wave pattern of the spleen by using abdominal CT images of a patient with liver cirrhosis, and found that they are different from those of a person with a normal liver. In the abdominal CT image of the patient with liver cirrhosis, there is a deep wave part on the left side of the spleen. In the case of the normal liver, there are waves on the left side, but they aren't deep. Therefore, the total area of waving parts of the spleen with liver cirrhosis is found to be greater than that of the spleen with the normal liver. Moreover, when examining circularity by abstracting the waves of the spleen from the image with liver cirrhosis, we found they are more circular than those of the spleen accompanied by a normal liver. This paper suggests an automatic method to diagnose liver cirrhosis by using the wave pattern of the spleen in abdominal CT images on the basis of the two principles. It tells us that we can judge if the liver has liver cirrhosis automatically, without the manual test of the ratio of caudate lobe to right lobe, only with the spleen.

Early Marginal Bone Loss around Submerged Implants According to the Patterns of Cover Screw Exposures (Submerged 임플란트에서 덮개나사 노출 양상에 따른 조기 변연골 상실)

  • Choi, Mee-Ra;Park, Chan-Jin
    • Journal of Dental Rehabilitation and Applied Science
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    • v.29 no.2
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    • pp.175-182
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    • 2013
  • The purpose of this study was to observe and analyze the initial marginal bone resorption changes according to the patterns of cover screw exposures during healing period followed by implants installation. Total 64 fixtures(TiUniteTM, NobelBiocare, Sweden) were installed in partially edentulous jaws of 28 patients, who were selected retrospectively and were shown at least one cover screw exposure. Cover screw exposures were defined at 1 month recall. According to the patterns of exposures, groups were categorized into group 1 (No exposure), group 2 (pin-point exposure), group 3 (less than 1/2 of cover screw), group 4 (more than 1/2 of cover screw), group 5 (total exposure). Periapical radiographs were taken in purpose of changes of marginal bone level between installation and 2 month recall. Healing abutments were secured on the exposure groups at 2 month recall. Results were as follows: 1. Marginal bone resorptions were identified whenever cover screws were exposed. 2. Group 2 and 3 were shown significantly increased bone loss more than other group (P <.05). 3. Group 4 and 5 were shown significantly increased bone loss more than group 1, however, less than other groups ( P <.05). Conclusionally, cover screw exposure may cause marginal bone resorptions, therefore, early connection of healing abutment is clinically helpful.

The Unexpected Volatility of Foreigners' Trading Behavior Effects on the Korean Stock Market Volatility (외국인 거래행태의 비기대변동성은 주식수익률의 변동성에 영향을 주는가)

  • Byun, Young tae
    • Management & Information Systems Review
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    • v.31 no.4
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    • pp.593-609
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    • 2012
  • This study is designed to investigate whether the information spillover effect is existed between the foreign investors' unexpected volatility of net purchasing intensity and the volatilities of returns in terms of daily closing stock return, overnight return, and daytime return, before and after financial crisis in Korea. The result of this study shows that there is negative information spillover effect between the foreign investors' unexpected volatility of net purchasing intensity and the volatility of daily closing stock return for time t-1. However, there is an opposite result for time t, showing positive information transmission effect. For the overnight return, the test result provides there is no statistical significance between the foreign investor's unexpected volatility of net purchasing intensity and the volatilities of return. In addition, I found that the information transmission effect is existed between the foreign investor's unexpected volatility of net purchasing intensity and the volatilities of the daytime return for the entire timeline.

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Usefulness of Median Modified Wiener Filter Algorithm for Noise Reduction in Liver Cirrhosis Ultrasound Image (간경변 초음파 영상에서의 노이즈 제거를 위한 Median Modified Wiener Filter 알고리즘의 유용성)

  • Seung-Yeon Kim;Soo-Min Kang;Youngjin Lee
    • Journal of the Korean Society of Radiology
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    • v.17 no.6
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    • pp.911-917
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    • 2023
  • The method of observing nodular changes on the liver surface using clinical ultrasonography is useful for diagnosing cirrhosis. However, the speckle noise that inevitably occurs in ultrasound images makes it difficult to identify changes in the liver surface and echo patterns, which has a negative impact on the diagnosis of cirrhosis. The purpose of this study is to model the median modified Wiener filter (MMWF), which can efficiently reduce noise in cirrhotic ultrasound images, and confirm its applicability. Ultrasound images were acquired using an ACR phantom and an actual cirrhotic patient, and the proposed MMWF algorithm and conventional noise reduction algorithm were applied to each image. Coefficient of variation (COV) and edge rise distance (ERD) were used as quantitative image quality evaluation factors for the acquired ultrasound images. We confirmed that the MMWF algorithm improved both COV and ERD values compared to the conventional noise reduction algorithm in both ACR phantom and real ultrasound images of cirrhotic patients. In conclusion, the proposed MMWF algorithm is expected to contribute to improving the diagnosis rate of cirrhosis patients by reducing the noise level and improving spatial resolution at the same time.

Success rate and marginal bone loss of Osstem USII plus implants; Short term clinical study (Osstem USII plus 임플란트의 단기간 성공률 및 변연골 흡수량 평가)

  • Kim, Sun-Keun;Kim, Jee-Hwan;Lee, Keun-Woo;Cho, Kyoo-Sung;Han, Dong-Hoo
    • The Journal of Korean Academy of Prosthodontics
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    • v.49 no.3
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    • pp.206-213
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    • 2011
  • Purpose: The aim of this study was to evaluate the clinical value of Osstem$^{(R)}$ USII plus system implants. Clinical and radiographic data were analyzed for 88 implants placed and functionally loaded for a 12 month period at the Yonsei University Dental Hospital. Materials and Method: Based on the patient's medical records, clinical factors and their effects on implant marginal bone resorption, distribution and survival rate were analyzed. The marginal bone loss was evaluated at implant placement and during a 6 to 12 months functional loading period. The independent sample t-test was used to evaluate the interrelationship between the factors (${\alpha}$=0.05), and one way repeated measures ANOVA was used to compare the amount of marginal bone resorption. Results: The cumulative survival rate for 88 implants was 100%. The marginal bone resorption from implant placement to prosthetic delivery was 0.24 mm and the average marginal bone resorption from prosthetic delivery to 12 months of functional loading was 0.19 mm. The total average bone resorption from implant placement to 12 months of functional loading was 0.43 mm. There were no statistically differences in the amount of marginal bone resorption when implants were placed in the maxilla or the mandible (P>.05), however, implants placed in the posterior areas showed significantly more marginal bone loss than those placed in the anterior areas (P<.05). Conclusion: Based on these results, the short term clinical success rate of RBM surface treated external connection domestic implants showed satisfactory results and the marginal bone loss was in accord with the success criteria of dental implants.

Effects of Dietary Mulberry Leaf on Loperamide-Induced Constipation in Rats (식이뽕잎이 흰쥐의 Loperamide로 유도된 변비에 미치는 영향)

  • Lee, Jae-Joon;Lee, Yu-Mi;Jung, Seoung-Ki;Kim, Keun-Young;Lee, Myung-Yul
    • Food Science and Preservation
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    • v.15 no.2
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    • pp.280-287
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    • 2008
  • We investigated the effect of dietary mulberry leaf powder (MP) on loperamide-induced constipation in rats. Male Sprague-Dawley rats were given MP in their diets at a concentration of 0% 5% and 10% for 33 days. Rats were divided into 4 groups: normal diet group (NOR), normal diet and loperamide treated group (MPL0), 5% MP and loperamide treated group (MPL5), and 10% MP and loperamide treated group (MPL10). Constipation was induced by subcutaneous injection of loperamide (1.5 mg/kg body weight/day) for the final 5 days of the experiment Supplemental MP had no effect on the food efficiency ratio, but it reduced body weight gain and food intake in a concentration dependent manner. Administration of loperamide decreased food intake. MP had a concentration-dependent effect on decreasing total cholesterol, LDL-cholesterol, and triglycerides and on increasing HDL-cholesterol. Loperamide had no significant effect on serum lipid profiles. Loperamide decreased the number and wet weight of fecal pellets and fecal water content MP increased the number and wet weight of fecal pellets and fecal water content in a dose-dependent manner. In addition, MP increased gut transit time and transit speed, and the guts of mts treated with MP plus loperamide were longer than those of mts treated with loperamide alone. These results indicate that MP is an effective treatment for constipation.