• Title/Summary/Keyword: Volume analysis

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Fundamental Study on The Heat Input Model of Hybrid Welding for The Finite Element Analysis (유한요소해석을 위한 하이브리드용접 입열모델 선정에 관한 기초적 연구)

  • 방한서;김영표
    • Proceedings of the KWS Conference
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    • 2003.11a
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    • pp.36-38
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    • 2003
  • In order to understand the basic knowledge on the model of heat source in hybrid welding, authors have conducted finite element analysis to calculate heat distribution using three heat source models of non-split type and split type(Volume, Volume-Volume, Volume-Surface). From the research result, we can confirm that Volume-Volume heat source of split type is suitable for the analysis of heat distribution.

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MR-based Partial Volume Correction for $^{18}$F-PET Data Using Hoffman Brain Phantom

  • Kim, D. H.;Kim, H. J.;H. K. Jeong;H. K. Son;W. S. Kang;H. Jung;S. I. Hong;M. Yun;Lee, J. D.
    • Proceedings of the Korean Society of Medical Physics Conference
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    • 2002.09a
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    • pp.322-323
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    • 2002
  • Partial volume averaging effect of PET data influences on the accuracy of quantitative measurements of regional brain metabolism because spatial resolution of PET is limited. The purpose of this study was to evaluate the accuracy of partial volume correction carried out on $^{18}$ F-PET images using Hoffman brain phantom. $^{18}$ F-PET Hoffman phantom images were co-registered to MR slices of the same phantom. All the MR slices of the phantom were then segmented to be binary images. Each of these binary images was convolved in 2 dimensions with the spatial resolution of the PET. The original PET images were then divided by the smoothed binary images in slice-by-slice, voxel-by-voxel basis resulting in larger PET image volume in size. This enlarged partial volume corrected PET image volume was multiplied by original binary image volume to exclude extracortical region. The evaluation of partial volume corrected PET image volume was performed by region of interests (ROI) analysis applying ROIs, which were drawn on cortical regions of the original MR image slices, to corrected and original PET image volume. From the ROI analysis, range of regional mean values increases of partial volume corrected PET images was 4 to 14%, and average increase for all the ROIs was about 10% in this phantom study. Hoffman brain phantom study was useful for the objective evaluation of the partial volume correction method. This MR-based correction method would be applicable to patients in the. quantitative analysis of FDG-PET studies.

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Elastic Analysis of an Unbounded Elastic Solid with an Inclusion Considering Composite Fiber Volume Fraction (섬유 체적분율을 고려한, 단일의 함유체를 포함한 무한고체에서의 탄성해석)

  • Lee, Jung-Ki;Han, Hui-Duck
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.31 no.1 s.256
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    • pp.89-96
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    • 2007
  • A volume integral equation method (VIEM) is applied for the effective analysis of plane elastostatic problems in unbounded solids containing single isotropic inclusion of two different shapes considering composite fiber volume fraction. Single cylindrical inclusion and single square cylindrical inclusion are considered in the composites with six different fiber volume fractions (0.25, 0.30, 0.35, 0.40, 0.45, 0.50). Using the rule of mixtures, the effective material properties are calculated according to the corresponding composite fiber volume fraction. The analysis of plane elastostatic problems in the unbounded effective material containing single fiber that covers an area corresponding to the composite fiber volume fraction in the bounded matrix material are carried out. Thus, single fiber, matrix material with a finite region, and the unbounded effective material are used in the VIEM models for the plane elastostatic analysis. A detailed analysis of stress field at the interface between the matrix and the inclusion is carried out for single cylindrical or square cylindrical inclusion. Next, the stress field is compared to that at the interface between the matrix and the single inclusion in unbounded isotropic matrix with single isotropic cylindrical or square cylindrical inclusion. This new method can also be applied to general two-dimensional elastodynamic and elastostatic problems with arbitrary shapes and number of inclusions. Through the analysis of plane elastostatic problems, it will be established that this new method is very accurate and effective for solving plane elastic problems in unbounded solids containing inclusions considering composite fiber volume fraction.

A Study on the Establishment of Design Criteria for Anchorage According to Port Characteristics

  • Park, Jun-Mo
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.23 no.3
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    • pp.279-286
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    • 2017
  • This study suggests design criteria to evaluate the availability of anchorage in Korea to contribute to ship safety by presenting necessary design criteria for anchorage volume according to port development. Accordingly, the concept of "necessary volume of anchorage" is introduced to evaluate the volume of anchorage available in Korea's major ports, and classify these ports into three types according to the characteristics of incoming ship. Numerical simulations designed using MATLAB-SIMULINK have been carried out to track the irregularly of arrival and, waiting times along with the environmental conditions that affect anchorage and necessary volume of anchorage have been suggested based on these tests. Finally, in order to complete a function equation analysis, the necessary volume of anchorage with reference to cargo volume is addressed using regression analysis as follows. Group $A-Y_{NA}=0.0002X_{HA}-3.67$, Group $B-Y_{NB}=0.0002X_{HB}-6.82$, Group $C-Y_{NC}=0.0001X_{HC}+9.02$. This study contributes to a review of anchorage volume from the perspective of harbor development.

A Study on the Cost-Volume-Profit Analysis in the Food Service Operation (호텔 영업장의손익분기점 분석에 관한 연구)

  • 김기영;강종헌
    • Culinary science and hospitality research
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    • v.3
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    • pp.165-179
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    • 1997
  • Cost-volume-profit analysis shows the relationship between these factors. The figures expressed in a break-even chart can be used planning control and decision making. The relation ships can also be helpful in understanding how all costs must be covered in menu pricing. Involved in these relationship is the contribution to overhead and profit, or contribution ratio. This study used the food service operation of H hotel. Assumed the FC would be 10% of the High Volume, the VC would be 76% of the high volume. And in the CVP of individual meals, selected labor cost of the VC, assumed labor cost would be 35% of the volume.

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Trading Volume and Overpricing of Lottery-type Stocks (거래량이 복권특성 종목의 기대수익률에 미치는 영향)

  • Yong-Ho Cheon
    • Asia-Pacific Journal of Business
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    • v.14 no.1
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    • pp.113-129
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    • 2023
  • Purpose - The purpose of this study is to examine whether trading volume amplifies the extent to which lottery-type stocks are overpriced, and whether economic sentiment index explains time-variation in the magnitude of the volume amplification effect. Design/methodology/approach - We examine monthly returns on 5x5 monthly bivariate portfolios formed by lottery characteristics (measured by maximum daily return) and trading volume. In addition, we perform time-series regression tests to examine how the volume amplification effect changes in high and low economic sentiment periods, after controlling for Fama-French three factors. Findings - Our bivariate portfolio analysis shows that the overpricing of lottery-type stocks are mostly pronounced among high trading volume stocks. In contrast, for low trading volume stocks, overpricing of lottery-type stocks appears to vanish. Furthermore, the amplification effect of trading volume on overpricing of lottery-type stock is concentrated in high economic sentiment periods. Research implications or Originality - This study is the first attempt to examine whether trading volume drives lottery-type stocks' overpricing in the Korean stock market. Furthermore, our analysis unveils the time-varying nature of volume amplification effect. The results suggest that trading volume might play a important hidden role in asset pricing, opening a new line of researches in the future.

Phase Identification of Nano-Phase Materials using Convergent Beam Electron Diffraction (CBED) Technique

  • Kim, Gyeung-Ho;Ahn, Jae-Pyoung
    • Applied Microscopy
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    • v.36 no.spc1
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    • pp.47-56
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    • 2006
  • Improvements are made to existing primitive cell volume measurement method to provide a real-time analysis capability for the phase analysis of nanocrystalline materials. Simplification is introduced in the primitive cell volume calculation leading to fast and reliable method for nano-phase identification and is applied to the phase analysis of Mo-Si-N nanocoating layer. In addition, comparison is made between real-time and film measurements for their accuracy of calculated primitive cell volume values and factors governing the accuracy of the method are determined. About 5% accuracy in primitive cell determination is obtained from camera length calibration and this technique is used to investigate the cell volume variation in WC-TiC core-shell microstructure. In addition to chemical compositional variation in core-shell type structure, primitive cell volume variation reveals additional information on lattice coherency strain across the interface.

Local nanofiller volume concentration effect on elastic properties of polymer nanocomposites

  • Shin, Hyunseong;Han, Jin-Gyu;Chang, Seongmin;Cho, Maenghyo
    • Multiscale and Multiphysics Mechanics
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    • v.1 no.1
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    • pp.65-76
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    • 2016
  • In this study, an influence of local variation of nanoparticulate volume fraction on the homogenized elastic properties is investigated. It is well known that interface effect is dependent on the radius and volume fraction of reinforced nanofillers. However, there is no study on the multiscale modeling and analysis of polymer nanocomposites including polydispersed nanoparticles with consideration of interphase zone, which is dependent on the volume fraction of corresponding nanoparticles. As results of numerical examples, it is confirmed that an influence of local variation of nanoparticulate volume fraction should be considered for non-dilute system such as cluster of nanoparticles. Therefore representative volume element analysis is conducted by considering local variation of nanoparticle volume fraction in order to analyze the practical size of cell including hundreds of nanoparticles. It is expected that this study could be extended to the multiparticulate nanocomposite systems including polydispersed nanoparticles.

Dental age estimation using cone-beam computed tomography: A systematic review and meta-analysis

  • Faezeh Yousefi;Younes Mohammadi;Mehrnaz Ahmadvand;Parnian Razaghi
    • Imaging Science in Dentistry
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    • v.53 no.2
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    • pp.91-99
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    • 2023
  • Purpose: This systematic review aimed to investigate the correlation between chronological age and dental pulp volume in cone-beam computed tomography (CBCT). Materials and Methods: The literature was searched in 4 databases(PubMed, Scopus, Web of Science, and Google Scholar). Within each study, the outcome of interest was the correlation (r) between chronological age and pulp volume. A random-effect meta-analysis was conducted. Subgroup analysis was carried out according to sex and tooth type. Results: Of 5,693 identified studies, 27 fulfilled the inclusion criteria and were selected for meta-analysis. These articles focused on single-rooted teeth (n=21), multi-rooted teeth (n=6), maxillary teeth (n=14), mandibular teeth (n=6), and maxillary and mandibular teeth (n=12). The relationship between chronological age and dental pulp volume was examined in the entire population (r= -0.67), men (r= -0.75), and women (r= -0.77) in single- and multi-rooted teeth. The results of the total population analysis showed a relatively strong negative relationship between age and pulp volume. Conclusion: This study suggested that CBCT is a reliable and repeatable tool for dental age estimation. A strong inverse relationship was observed between pulp chamber volume and age. Further studies on the correlation between chronological age and pulp volume of multi-rooted teeth may be beneficial.

Failure Analysis of Reinforced Concrete Slabs using Pseudo-Volume Control Method (의사체적제어법을 이용한 철근콘크리트 슬래브의 파괴거동 해석)

  • 심상효;송하원;최강룡;남상혁;변근주
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.04a
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    • pp.577-582
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    • 2000
  • The pseudo-volume control method is developed for the failure analysis of RC slabs, by adding pressure node into layered shell element utilizing in-plane constitutive models of reinforced concrete and layered formulation. For the failure analysis of RC slabs n this paper, geometric nonliearity is also considered in the analysis. The validity of the pseudo-volume control method is verified by comparing analysis results and existing experimental results.

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