• Title/Summary/Keyword: Effective volume

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Comparison Analysis of Donor Liver Volumes Estimated with 3D Magnetic Resonance and 3D Computed Tomography Image Data

  • Kim, Myeong-Seong;Park, Kyeong-Seok;Cho, Jae-Hwan
    • Journal of Magnetics
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    • v.19 no.3
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    • pp.261-265
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    • 2014
  • Three-dimensional computed tomography is an effective tool to estimate the liver volume of living donors for the live liver transplantation. When additional operation is required, magnetic resonance imaging is conducted to determine the safety of the donor. This study compared the accuracy of magnetic resonance imaging and computed tomography in estimating 3D liver volume of 23 male and 7 female donors who underwent both magnetic resonance imaging and computed tomography tests before the transplantation. The analysis was conducted to see whether the liver's estimated total volumes and the left lobe volumes obtained from 3D-magnetic resonance imaging and 3D-computed tomography were identical. Volumes of the right lobe estimated with 3D-magnetic resonance imaging and 3D-computed tomography were compared with the actual volume of the right lobe harvested in the operating room because the volume of the right lobe is an important determinant in the safety of the donor. The total volume of the liver estimated from 3D-magnetic resonance imaging and 3D-computed tomography differed (1238.1904 units and 1402.364 units respectively). The left lobe volume of the liver estimated with 3D-magnetic resonance imaging and 3D-computed tomography also differed (450.530 units and 554.490 units, respectively). The right lobe volume of the liver estimated with 3D-magnetic resonance imaging and 3D-computed tomography were 787.660 units and 847.545 units, respectively, while the actual average right lobe volume of the harvested liver was 678.636 units. 3D-computed tomography has been widely used to estimate the right lobe volume of the donors' liver. However, 3D-magnetic resonance imaging was also very effective in estimating the volume of the liver. Thus, 3D-magnetic resonance imaging is also expected to become an important tool in determining the safety of the donors before transplantation.

Effects of Carbon Black Morphology and Loading Level on the Physical Properties of Natural Rubber Compound (카본블랙의 형태 특성이 천연고무 배합 물성에 미치는 영향)

  • Choi, Kwan-Young;Yoon, Jae-Ryong;Kim, Hwi-Joong
    • Elastomers and Composites
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    • v.33 no.1
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    • pp.17-26
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    • 1998
  • Natural rubber was filled with 8 commercial carbon blacks covering range of rubber-grade products at different levels of filler loadings in order to investigate physical compound and vulcanizate properties. It was found that the curves of rubber property vs filler loading of both uncured compounds and vulcanizates can be superposed to one single master curve by introducing an effective volume fraction which is based on CDBP. The effective volume fraction, $V_{EFF}$ was utilized to explain the variation of the stiffness of all rubber compounds. The surface area-corrected effective volume fraction, V', was utilized to explain the formation of bound rubber, rebound and lambourn wear.

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Variation of Dielectric Constant with the Volume Fraction of Pyrochlore Phae in the PMN-Polychlore Diphasic System ; Application of General Effective Media Equation (Pyrochlore상의 부피분율에 따른 PMN-Pyrochlore 2상 혼합체의 유전율변화;General Effective Media식의 적용)

  • 허강일;김정주;김남경;김진호;조상희
    • Journal of the Korean Ceramic Society
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    • v.30 no.1
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    • pp.78-84
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    • 1993
  • In PMN-pyrochlore phase mixtures, dielectric constant was measured as a function of the volume fraction of pyrochlore phase and considered with general effective media(GEM) equation. For the application of GEM equation to this system, the critical volume fraction(Vc) where connectivity between the perovskite PMN and pyrochlore phase changed from 0-3 to 3-3, was determined based on the each particle size ratio of two phases with microstructural observation. And then the t value was determined from modified percolation powder-law dependence ( K-Kc (V-Vc)t). In the case of applying such values of t and Vc to the GEM equation, which provided a reasonable fit to the measured dielectric constant within the experimental error range.

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Consideration of Heat Recovery Ventilator from Ventilating Standpoint (환기관점에서 본 열교환 환기유니트)

  • Song, Jun-Won;Kang, Il-Kyung;Kim, Tae-Hee;Shin, Yong-Sup;Park, Jae-Sung;Choi, Won-Young
    • Proceedings of the SAREK Conference
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    • 2006.06a
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    • pp.417-422
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    • 2006
  • On trends of 'well-being', heat recovery ventilators(HRV) are recently installed in high rise buildings. HRV is not energy saving instrument but ventilating one. But many people have not been aware of the accurate fact. In this study, performances of HRV are tested under foreign and domestic standards. Especially air-tightness is measured three times by using gas concentration method and pressing equipment. Wet effective ventilating air volume is acquired by solving gas concentration equations. After research air-tightness and effective ventilating air volume must be more focused on than heat transfer efficiency to select the optimal HRV. Heat transfer efficiency must be adjusted by air-tightness results.

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Analyzing the Reduction of Runoff and Flood by Arrangements of Stormwater Storage Facilities (우수저류시설의 배치방법에 따른 유출 및 침수피해 저감효과 분석)

  • Park, Changyeol;Shin, Sang Young;Son, Eun Jung
    • Journal of Korean Society on Water Environment
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    • v.29 no.1
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    • pp.45-54
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    • 2013
  • This study analyzes the reduction effects of runoff and flood damage through different arrangements of stormwater storage facilities. Three scenarios based on the spatial allocation of storage capacity are used: concentrated, decentralized and combinative. The characteristics of runoff and flood damage by scenario are compared. The XP-SWMM model is used for runoff simulation by the probable rainfall of return period. The result shows that the concentrated arrangement of storage facilities is most effective to reduce the amount of peak flow and to delay the time of peak flow. Yet, while the concentrated arrangement is most effective to reduce the inundation damage, it is not effective to reduce runoff volume. The decentralized arrangement is most effective to reduce runoff volume. The combinative arrangement is effective not only the runoff reduction but also the reduction of flood damage. The result indicates that the flood mitigation strategies against heavy rainfall need to consider decentralized on-site arrangement for the reduction of runoff volume along with concentrated off-site arrangement of storage facilities.

Comparative Analysis on the Delay Between Multi-legged Roundabout and Signalized Intersection (다지 회전교차로와 신호교차로의 지체 비교 분석)

  • Han, Su-San;Park, Byung-Ho
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.9 no.6
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    • pp.83-93
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    • 2010
  • The roundabout is a green transportation system which reduces the accident, the congestion cost and greenhouse effect. The purpose of the study is to analyze the multi-legged roundabout's efficiency. In pursuing the above, this study gives particular attention to building the optimal network of multi-legged roundabout and intersections, developing the scenarios for analysis reflected by the proportion of entering traffic volume of main and minor roads, and comparatively analyzing the average delay per car using VISSIM. The main results are as follows. First, when the entering traffic volume are less than 3,500pcph, the 5-legged single and double-lane roundabout are all analyzed to be more effective than intersection. Second, when the entering traffic volume are less than 3,600pcph, the 6-legged single-lane roundabout is analyzed to be more effective than intersection. The 6-legged double-lane roundabout is analyzed to be more effective than intersection. The 6-legged double-lane roundabout is analyzed to be more effective than intersection in all cases of entering volume.

A Systematic Review and Meta Analysis of Randomized Controlled Trials of the Clinical Effect on Taking a Herbal Medicine on Postpartum Lactation (한약 복용이 산후 유즙분비에 미치는 효과에 대한 체계적 문헌고찰)

  • Lee, Hye-Jung;Lee, Su-Jeong;Hwang, Deok-Sang;Lee, Chang-Hoon;Jang, Jun-Bock;Lee, Jin-Moo
    • The Journal of Korean Obstetrics and Gynecology
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    • v.34 no.3
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    • pp.137-156
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    • 2021
  • Objectives: The purpose of this study is to assess the effect of taking herbal medicine for the postpartum lactation. Methods: We searched 9 databases for recent three years, that contained four english, two chinese, one japanese and two korean database from September 17, 2016 to December 31, 2020. Randomized controlled trials (RCTs) were eligible. Measurement of outcome included total curative effective rate, volume of lactation, volume of milk supplement, and serum prolactin concentration. The risk of bias was assessed by two independent authors using the Cochrane risk of bias tool. Results: Total 725 of studies was screened, 11 RCTs were finally selected. Number of participants per study ranged from 60 to 257. The treatment group of taking a herbal medicine is effective for improving total curative effective rate, volume of lactation, volume of milk supplement, and serum prolactin concentration compared with control group. Because most of the studies had considerable heterogeneity in terms of type of intervention and comparison for outcome measurement, meta analysis for quantitative analysis was impossible. Conclusions: This studies showed that taking a herbal medicine is effective on increasing volume of lactation and speeding up the start of the first breastfeeding. However, included studies suffered from incomplete reporting, high or unclear risk of bias and substantial heterogeneity between studies. In the Future, further high-quality RCTs are needed to prove effectiveness of herbal medicine for breastfeeding and reduce the risk of bias.

Effective Longitudinal Shear Modulus of Continuous Fiber-Reinforced 3-Phase Composites (연속섬유가 보강된 3상 복합재료의 종방향 전단계수 해석)

  • Jeong, Tae-Heon;Lee, Dong-Joo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.20 no.9
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    • pp.2782-2791
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    • 1996
  • The effective longitudinal shear modulus(LSM) of continuous composites is studied theoretically and numerically using 3-phase unit cell model. Circular, hexagonal and rectangular shapes of reinforced fiber are considered to predict the shear modulus as a function of elastic modulus of each phase and volume fraction of interphase and reinforced fiber. It is found that rectangular fiber shape in low fiber volume fraction($v_f$<30%) and circular fiber shape in high volume fraction($v_f$>40%) shows the higher longitudinal shear modulus. Also the obtained values of LSM for rectangular array and by numerical analysis are higher than those of hexagonal array and by theoretical analysis respectively. The reinforcing effects of interphase are more significant in cases of higher fiber volume fraction and circular fiber shape. Not only the spatial distribution and shape of reinforcing fiber but also the volume of interphase have a pronounced effects on the overall LSM. It is also found that the tangent moduous of 2-and 3-phase polymer matrix composites is insensitive to the shape and distribution of reinforcing fibers.

Selecting of Interpolation for Extraction of Optimal Submarine Topographic Information. (최적해저지형정보 추출을 위한 보간법 선정)

  • 이종출;김희규;김남식;김성호
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2004.04a
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    • pp.571-576
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    • 2004
  • In this study, we selected the most effective interpolation method using both the data of sounding the depth of submarine topography and volume-production computer program. After processing the data by volume-production program, and then we selected the most effective interpolation method which nearest actual value of dredged soil quantity. Thus, these interpolation could be used for describing the optimal submarine topography.

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Adaptive B-spline volume representation of measured BRDF data for photorealistic rendering

  • Park, Hyungjun;Lee, Joo-Haeng
    • Journal of Computational Design and Engineering
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    • v.2 no.1
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    • pp.1-15
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    • 2015
  • Measured bidirectional reflectance distribution function (BRDF) data have been used to represent complex interaction between lights and surface materials for photorealistic rendering. However, their massive size makes it hard to adopt them in practical rendering applications. In this paper, we propose an adaptive method for B-spline volume representation of measured BRDF data. It basically performs approximate B-spline volume lofting, which decomposes the problem into three sub-problems of multiple B-spline curve fitting along u-, v-, and w-parametric directions. Especially, it makes the efficient use of knots in the multiple B-spline curve fitting and thereby accomplishes adaptive knot placement along each parametric direction of a resulting B-spline volume. The proposed method is quite useful to realize efficient data reduction while smoothing out the noises and keeping the overall features of BRDF data well. By applying the B-spline volume models of real materials for rendering, we show that the B-spline volume models are effective in preserving the features of material appearance and are suitable for representing BRDF data.