• 제목/요약/키워드: Volume/Mass

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Effect of Gender Difference on the Functional Asymmetry during Preferred Walking Speed

  • Hyun, Seunghyun;Ryew, Checheong
    • International journal of advanced smart convergence
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    • 제9권2호
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    • pp.49-57
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    • 2020
  • We have not identified on what gender difference during gait at a pace of one's preferred velocity effects on the function of bilateral lower limb. This study was undertaken to investigate a difference of gait strategy by gender during gait at a one's preferred velocity of participants of adult male and female (n=20). Cinematographic data for motion analysis, ground reaction force (GRF) variables, and muscle volume of lower limb were analyzed. Significant difference of variables on movement of center of mass whole body, joint angle and moment of lower limb, and ground reaction force were tested by 2-way ANOVA analysis (P<0.05). Male group showed more muscle volume than female, and both showed more volume in dominant leg than non-dominant. Main effect by bilateral leg during gait showed higher difference in right than left leg in change of vertical position of center of mass (maximal, minimal). Main effect by gender in vertical change of position and velocity of center of mass showed higher difference in male than female (maximal, minimal). Hip joint showed more flexed and extended angle in male than female, and also dorsiflexion of ankle and flexion moment of knee and hip joint showed higher in male than female group. Therefore, this result was assumed that dominant showed furthermore more contribution for propulsive function than non-dominant leg. Gender difference showed in strategy controlling of biomechanical characteristics, and perhaps influenced by muscle volume.

유방조직의 밀도와 체질량지수와의 상관관계 (Correlation of Breast Tissue Density and Body Mass Index)

  • 양정학;이택종
    • Archives of Plastic Surgery
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    • 제37권6호
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    • pp.732-735
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    • 2010
  • Purpose: In performing breast reconstruction, making symmetrical breast is still a challenge. A precise estimate of the volume of the breast specimen is necessary to reconstruct a symmetrical and aesthetically pleasing breast. This study aims at finding out the relationship with breast tissue density and body mass index designed to apply for breast reconstruction. Methods: By using the Archimedes' principle, the authors calculated the volume of the breast specimen and drew a correlation between the density of breast specimen and BMI. From October 2002 to November 2004, this method was used on 197 patients to predict breast volume for TRAM flap reconstruction. Results: The mean density was 0.9954g/cc and had no correlation with BMI (p-value=0.069). There was no difference between denstiy of breast tissue after skin spared mastectomy and that of breast tissue after nipple spared mastectomy. Conclusion: These data will be helpful to predict the needed volume for breast reconstruction.

정상 성인의 신체조성과 폐 기능의 연관성 (Correlation between Body Composition and Lung Function in Healthy Adults)

  • 김현승;조성현
    • 대한통합의학회지
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    • 제8권2호
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    • pp.53-61
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    • 2020
  • Purpose : We investigated the correlation between body composition and lung function in healthy adults. Methods : This study included 204 healthy adults in whom all measurements were obtained once, and all data were analyzed using the SPSS software for Windows, version 22.0. Pearson's correlation analysis was performed to determine the correlation between body composition (represented by the total body water, protein mass, soft lean mass, mineral mass, basal metabolic rate, fat-free mass, skeletal muscle mass, and body fat percentage) and lung function (represented by the forced vital capacity [FVC], forced expiratory volume in 1 second [FEV1], the FEV1/FVC ratio, maximum voluntary ventilation [MVV], maximum expiratory pressure [MEP], and the maximum inspiratory pressure [MIP]). All measurements were obtained by two investigators to improve reliability. A significance level of α=.05 was used to verify statistical significance. Results : Among the lung function measurements obtained in both men and women, the FVC, FEV1, MVV, and MIP were positively correlated with the total body water, protein mass, soft lean mass, mineral mass, basal metabolic rate, fat-free mass, and skeletal muscle mass in men (p<.05). The FEV1/FVC ratio was negatively correlated with the total body water, soft lean mass, mineral mass, basal metabolic rate, fat-free mass and the body fat percentage (p<.05). Notably, the FVC, FEV1, and MVV were positively correlated with the total body water, protein mass, soft lean mass, mineral mass, basal metabolic rate, fat-free mass, and skeletal muscle mass in women (p<.05). Conclusion : This study showed a significant correlation between body composition and lung function in healthy adults. In combination with future studies on lung function, our results can provide objective evidence regarding the importance of prevention of lung disease, and our data can be utilized in rehabilitation programs for patients with respiratory diseases.

정적연소기에서 토치의 노즐 직경에 따른 메탄의 연소특성 파악 (A Study on Combustion Characteristics of Methane Fuel according to Torch Nozzle Diameter in a Constant Volume Combustion Chamber)

  • 이정만;권순태;박찬준;엄인용
    • 한국가시화정보학회지
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    • 제8권1호
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    • pp.19-24
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    • 2010
  • Five different size of orifice were applied in a constant volume combustion chamber for evaluating the effects of torch-ignition on combustion. The initial flame development and flame propagation were analyzed by the mass burned fraction and combustion enhancement rate. The combustion pressures were measured to calculate the mass burned fractions and the combustion enhancement rates. In addition, the flame propagations were visualized by the shadowgraph method for the qualitative comparison. The result showed that the combustion pressure and mass burned fraction were increased when using the torch-ignition device. The combustion enhancement rates of torch-ignition cases were improved in comparison with conventional spark ignition. Finally, the visualization results showed that the torch-ignition induced faster burn than conventional spark ignition due to the earlier transition to turbulent flame and larger flame surface, during the initial stage.

체성분 분석과 골연령 측정을 통한 취학 전 아동의 성장에 대한 임상연구 (A Clinical Study on Growth of Children Based on Analyzing Body compositions And Measuring Bone Age)

  • 윤혜진;이유진;백정한
    • 대한한방소아과학회지
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    • 제23권2호
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    • pp.131-144
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    • 2009
  • Objectives : The purpose of this study is to have better data and to make efficient clinical reviews on pre-school children's growth based on two measurements; Body composition for measuring body volume and bone age for potential growth. Methods : The study was conducted with 221 children(118 of boys and 103 of girls) from three kindergartens. Body compositions(soft lean mass, body fat mass, percent body fat) were measured by bioelectrical impedance analysis, bone age was measured by bone density through ultrasonic image of calcaneus. Results and Conclusions : 1. The higher level on weight or BMI, the more averages of soft lean mass, body fat mass, percent body fat. 2. The average bone ages and bone age-chronological age were lower in under 50 percentile's group, but it was higher in upper 50 percentile's group. Also, children with high BMI had older in bone ages and bone age-chronological age. 3. The higher in height percentile based on the bone age; there were more soft lean mass. 4. The averages of bone age and bone age-chronological age were significantly decreased, the more percentiles of height according to bone age were big, they were higher than total average in under 50 percentile's group of height, lower than total average in over 50 percentile's group of height in both boys and girls. 5. The average of MPH were significantly decreased in top percentiles of children's height distribution. Also, in the upper percentiles of height distribution based on bone age were big in only boys. 6. The body compositions(soft lean mass, body fat mass, percent body fat) were related to body volume growth, which can he measured by weight or BMI. The bone age, bone age-chronological age, and MPH were related in terms of hight. The body volume growth was a little hit related with potential growth.

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정상체중과 과체중 여대생을 대상으로 컵의 형태에 따른 인지량의 차이에 관한 연구 (Difference in Volume Perception according to Cup Shape in Normal Weight and Overweight Female College Students)

  • 이명옥;장은재
    • 대한영양사협회학술지
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    • 제20권1호
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    • pp.63-69
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    • 2014
  • The volume perception of water according to cup shape was examined in female college students divided into a normal weight group (<23 body mass index, n=51) and an overweight group (${\geq}$23 body mass index, n=48). The perceived water volume was recorded by participants after they observed the water volume in cups with different shape (highball and tumbler) and with different base height (high base and low base), which contained the same amount of water (150 ml). The normal weight group perceived a water volume of 238.5 ml (highball) and 201.6 ml (tumbler) for the high base cups. The overweight group perceived a volume of 245.6 ml (highball) and 188.8 ml (tumbler). For the low base cups, the normal weight group perceived a water volume of 207.8 ml (highball) and 104.1 ml (tumbler). The overweight group perceived a volume of 202.2 ml (highball) and 100.4 ml (tumbler). Both the normal weight and overweight groups perceived significantly more liquid in the highball cups compared to the tumbler cups. In addition, both groups perceived significantly more liquid in the high base cups compared to the low base cups. However, there were no significant differences in the estimated variance of perceived volume between the normal weight and overweight groups according to the cup shape and cup base height. In conclusion, cup shape and base height potentially affects volume perception. Therefore, modifying cup shape may be used in a weight control program to help control caloric beverage consumption.

Membrane Inlet-based Portable Time-of-flight Mass Spectrometer for Analysis of Air Samples

  • Kim, Tae-Kyu;Jung, Kyung-Hoon;Yoo, Seung-Kyo;Jung, Kwang-Woo
    • Bulletin of the Korean Chemical Society
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    • 제26권2호
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    • pp.303-308
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    • 2005
  • A miniaturized time-of-flight mass spectrometer with an electron impact ionization source and sheet membrane introduction has been developed. The advantages and features of this mass spectrometer include high sensitivity, simple structure, low cost, compact volume with field portability, and ease of operation. A mass resolution of 400 at m/z 78 has been obtained with a 25 cm flight path length. Under optimized conditions, the detection limits for the volatile organic compounds (VOCs) studied were 0.2-10 ppm by volume with linear dynamic ranges greater than three orders of magnitude. The response times for various VOCs using a silicone membrane of 127 $\mu$m thickness were in the range 4.5-20 s, which provides a sample analysis time of less than 1 minute. These results indicate that the membrane introduction/time-of-flight mass spectrometer will be useful for a wide range of field applications, particularly for environmental monitoring.

반응적 교수법에 의한 고등학교 1학년 학생들의 질량 보존과 부피 변화에 대한 사고 변화 분석 (The Analysis of Thought Change of 11th Grade Students related to Conservation of Mass and Volume Change by Responsive Teaching)

  • 조나연;백성혜
    • 대한화학회지
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    • 제64권5호
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    • pp.304-317
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    • 2020
  • 이 연구는 중소도시에 소재한 고등학교 1학년 학생 4명을 대상으로 반응적 교수법의 효과를 알아보았다. 이를 위하여 반응적 교수법의 3단계를 세분화하여 6단계로 구성하였다. 1단계는 학생들의 거시적 생각 드러내기, 2단계는 학생들의 초기 미시적 생각 이끌어내기, 3단계는 입자에 대한생각을 학문과 연결하기, 4단계는 교사가 개입하여 입자에 대한 학습자의 생각을 명료히 하기, 5단계는 학생 생각 심화하기, 6단계는 학생 생각 확장하기였다. 4단계까지의 과정을 통해 질량의 원인은 원자이며, 부피의 원인은 분자라는 학생들의 생각이 명료하게 드러났다. 5단계에서 학생들은 양성자와 중성자가 존재하는 공간을 매우 작으므로 분자 자체의 부피는 무시한다는 개념에 도달하였다. 그리고 생각을 확장하는 6단계에서 입자의 부피를 무시한 질점의 개념으로 분자 운동을 설명하였다. 이를 통해 학생들은 아보가드로의 법칙에서 요구되는 입자의 질량보존과 부피변화의 관계에 대한 관점을 획득하고, 어떤 시스템은 직접 관찰하기에 너무 작거나, 너무 크거나, 너무 빠르거나, 너무 느려서 간접적으로만 연구될 수 있음을 인식하였다.

An Optimized Mass-spring Model with Shape Restoration Ability Based on Volume Conservation

  • Zhang, Xiaorui;Wu, Hailun;Sun, Wei;Yuan, Chengsheng
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제14권4호
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    • pp.1738-1756
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    • 2020
  • To improve the accuracy and realism of the virtual surgical simulation system, this paper proposes an optimized mass-spring model with shape restoration ability based on volume conservation to simulate soft tissue deformation. The proposed method constructs a soft tissue surface model that adopts a new flexion spring for resisting bending and incorporates it into the mass-spring model (MSM) to restore the original shape. Then, we employ the particle swarm optimization algorithm to achieve the optimal solution of the model parameters. Besides, the volume conservation constraint is applied to the position-based dynamics (PBD) approach to maintain the volume of the deformable object for constructing the soft tissue volumetric model base on tetrahedrons. Finally, we built a simulation system on the PHANTOM OMNI force tactile interaction device to realize the deformation simulation of the virtual liver. Experimental results show that the proposed model has a good shape restoration ability and incompressibility, which can enhance the deformation accuracy and interactive realism.