• 제목/요약/키워드: Effective volume

검색결과 2,423건 처리시간 0.034초

Study on the unidirectional compaction of terminal cables in the CICC joint

  • 남현일;이호진;박재학;홍계원
    • Progress in Superconductivity
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    • 제3권2호
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    • pp.218-223
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    • 2002
  • The void volume fraction of cables is one of the effective parameters to characterize the joints of superconducting magnet. Because electrical resistance and cooling stability in the CICC (Cable-in-Conduit Conductors) joint are governed by the void volume fraction, it should be controlled constantly in the termination of cable. The change of cross-section shape in the cable was fecund during the unidirectional compaction of terminal sleeve. The non-uniform thickness of the sleeve after compaction is expected because the loading is not taxi-symmetric, and the plastic flow is also not axi-symmetric. The CICC was compacted from 45% void volume fraction to 15% by using two-piece compaction jig, which could be pressed mini-directionally. Commercial code, ABAQUS, was used to analyze the plastic flow in the sleeve during the unidirectional compaction. The increment of radius of curvature of compaction jig could minimize the change of the deformed shape of cables. The calculated results were agreed with the experimental observations.

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진동-음향 상반 원리에 이용되는 음원의 유효 면적 측정 (The Application of Equivalent Area to the Volume Velocity for Using the Vibro-acoustical Reciprocity)

  • 고강호
    • 소음진동
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    • 제9권5호
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    • pp.943-948
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    • 1999
  • This paper proposes a feasible and effective method for measuring the mechanical-acoustic transfer function by the application of equivalent area and velocity transfer function, a manifestation of the vibro-acoustical reciprocity principle. On the contrary to the volume velocity used in traditional method, the equivalent area is a peculiar raidation characteristics of sound sources and not influenced by any input signal for driving sound source. This invariant property of equivalent area can get rid of boresome works to measure the volume velocity of a sound source every time the driving signal is changed. Moreover, this method has a remarkable advantage to use a general loudspeaker as an accoustic exciter without the assumption of point source and can be applied to all kinds of sound sources even if they are not omni-directional sources.

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녹색 신교통 시스템 바이모달트램의 비용-수요 공급곡선을 고려한 도시 대중교통체계 적용 특성 분석 (Analysis of Applicability in the Public Transportation System considering the Cost-volume Supply Curve of New Transit System Bi-Modal Tram)

  • 김홍석;김량균;함재현;전재청;윤희택
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2010년도 춘계학술대회 논문집
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    • pp.2303-2308
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    • 2010
  • We studied the cost-volume supply characteristic of public transportation systems focused on Bi-modal Tram in the main cities to analyze the applicability and status for the new transit system Bi-modal Tram as public transportation system. The operation cost considering the characteristic of vehicle, facilities, operation and average cost for respective public transportation system and the time cost considering the travel and transfer time are defined to the social cost, and the cost-volume supply curve is based on this social cost. The cost-volume supply characteristic between public transportation modes in the city is determined on the basis of cost-volume supply curve. Through the comparison between cost-volume supply characteristic of main transportation systems, it is analyzed about the relation between public transportation systems in the city and the characteristic for proper service provision. The application of Bi-modal Tram in the city is concluded that it is effective to reduce the social cost on the existing public transportation system.

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신경망을 이용한 컨테이너 물동량 예측에 관한 연구 (A Study on the Forecasting of Container Volume using Neural Network)

  • 박성영;이철영
    • 한국항해항만학회지
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    • 제26권2호
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    • pp.183-188
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    • 2002
  • 컨테이너 물동량 예측은 항만과 항만의 개발에 있어서 매우 중요하다. 일반적으로 이동평균법, 지수평활법, 회귀분석과 같은 통계적인 방법들은 물동량 예측에서 많이 사용되어졌다. 하지만, 컨테이너 물동량 예측에 영향을 주는 여러 가지 요소들을 고려해 보면 다중병렬처리시스템인 신경망을 이용하는 것이 효과적이다. 본 연구는 신경망의 역전파학습알고리즘을 이용하여 컨테이너 활동량을 예측하였다. 신경망을 이용하여 영향력 있는 요소들을 선별하였으며, 선별된 요소들을 이용하여 물동량 예측을 하였다. 또한 제안된 신경망 알고리즘과 통계적인 방법의 예측들을 비교하였다.

쌀빵의 제빵 적성에 대한 HPMC와 복합 효소 첨가 수준 영향 (The Effects of the Different Percentages of HPMC and Enzymes on Making Rice Bread)

  • 김상숙;정혜영
    • 한국식생활문화학회지
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    • 제34권4호
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    • pp.456-462
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    • 2019
  • This study investigated the bread-making properties of rice bread supplemented with HPMC (hydroxypropyl methylcellulose) 1~3% and gluzyme (glucose oxidase), fungamyl (fungal ${\alpha}$-amylase) and pentopan (xylanase+hemicellulases) (0.0015~0.0090%). The viscoelastic properties of the dough with HPMC 1~3% were analyzed. When the rice flour was supplemented with HPMC 1~3%, the viscoelastic properties of the dough tended to increase as the amount of added HPMC was increased. The physicochemical characteristics of the rice bread with HPMC, gluzyme, fungamyl, and pentopan were analyzed. Supplementing the rice flour with HPMC, gluzyme, fungamyl, and pentopan had a significant effect on the volume (p<0.01) and specific volume (p<0.001) of the rice bread. Supplementing the rice flour with 3% HPMC and 0.0045% or 0.0090% pentopan had a significant effect on increasing the volume (p<0.01) and specific volume (p<0.001) of the rice bread. Supplementing the rice flour with 3% HPMC, 0.0023% gluzyme and 0.0015% fungamyl had a significant effect on increasing the volume (p<0.01) and specific volume (p<0.001) of the rice bread. These results suggest that supplementing the rice flour with HPMC, gluzyme, fungamyl and pentopan is effective for the production of rice bread.

반죽의 냉동과 저장 조건에 따른 빵의 품질 특성 (Quality Characteristics of Wheat Flour Breads with the Doughs Frozen at the Different Freezing and Storage Conditions)

  • 고봉경
    • 한국식품과학회지
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    • 제34권3호
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    • pp.413-418
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    • 2002
  • 제빵에 이용 할 반죽을 발효하거나 발효하지 않은 상태로 다섯 가지의 다른 냉동 및 저장 환경에서 냉동하고 일주일간 저장하여 해동 한 후 제조된 빵의 품질을 비교하였다. 냉동속도가 빠르더라도 발효한 후 냉동된 반죽은 빵의 부피가 감소하였으며 이러한 문제점은 침지식 냉동 방식에서도 해결되지 않았다. $-70^{\circ}C$의 초저온 냉동은 $-20^{\circ}C$ 침지식 냉동고에 비하여 냉동 온도가 매우 낮으나, 냉동 속도도 느리고 해동 후 재 발효하여도 빵의 부피가 작아서 효과적인 냉동 방법이 되지 못하였다. 반면 냉동 속도는 느리지만 $-20^{\circ}C$ 공기 송풍식 냉동고가 $-70^{\circ}C$ 공시 송풍식 냉동고보다 냉동에 따른 장해가 적어서 반죽의 발효가 잘되었다. 동일한 온도일 때는 침지식 냉동이 더욱 효과적이었으며 침지식 가운데도 온도가 더 높은 $-10^{\circ}C$ 냉동이 가장 효과적이어서 발효하지 않고 냉동하여 재 발효 할 경우 대조구보다도 오히려 반죽의 발효가 잘되어 빵의 부피가 더 컸다. 따라서 본 연구에 이용한 방법 가운데 $-70^{\circ}C$ 공기 송풍식 냉동고에서 냉동, 저장하는 것이 가장 비효율적이며 침지식 냉동방법들이 냉동 온도가 높더라도 오히려 해동 후 발효 장해가 적어서 효율적이었다. 위의 실험 결과를 종합하였을 때, 냉동 전에 반죽을 발효하지 않고 $-10^{\circ}C$ 침지식 냉동고에서 냉동하여 저장하거나, $-20^{\circ}C$ 침지식 냉동고에서 초기에 냉동을 하고, $-20^{\circ}C$ air freezer에 저장하는 방법이 가장 효과적이었다.

Elastic properties of CNT- and graphene-reinforced nanocomposites using RVE

  • Kumar, Dinesh;Srivastava, Ashish
    • Steel and Composite Structures
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    • 제21권5호
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    • pp.1085-1103
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    • 2016
  • The present paper is aimed to evaluate and compare the effective elastic properties of CNT- and graphene-based nanocomposites using 3-D nanoscale representative volume element (RVE) based on continuum mechanics using finite element method (FEM). Different periodic displacement boundary conditions are applied to the FEM model of the RVE to evaluate various elastic constants. The effects of the matrix material, the volume fraction and the length of reinforcements on the elastic properties are also studied. Results predicted are validated with the analytical and/or semiempirical results and the available results in the literature. Although all elastic stiffness properties of CNT- and graphene-based nanocomposites are found to be improved compared to the matrix material, but out-of-plane and in-plane stiffness properties are better improved in CNT- and graphene-based nanocomposites, respectively. It is also concluded that long nanofillers (graphene as well as CNT) are more effective in increasing the normal elastic moduli of the resulting nanocomposites as compared to the short length, but the values of shear moduli, except $G_{23}$ of CNT nanocomposite, of nanocomposites are slightly improved in the case of short length nanofillers (i.e., CNT and graphene).

3차원 Volume PIV의 개발 (Development of 3-D Volume PIV)

  • 최장운;남구만;이영호;김미영
    • 대한기계학회논문집B
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    • 제27권6호
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    • pp.726-735
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    • 2003
  • A Process of 3-D Particle image velocimetry, called here, as '3-D volume PIV' was developed for the full-field measurement of 3-D complex flows. The present method includes the coordinate transformation from image to camera, calibration of camera by a calibrator based on the collinear equation, stereo matching of particles by the approximation of the epipolar lines, accurate calculation of 3-D particle positions, identification of velocity vectors by 3-D cross-correlation equation, removal of error vectors by a statistical method followed by a continuity equation criterior, and finally 3-D animation as the post processing. In principle, as two frame images only are necessary for the single instantaneous analysis 3-D flow field, more effective vectors are obtainable contrary to the previous multi-frame vector algorithm. An Experimental system was also used for the application of the proposed method. Three analog CCD camera and a Halogen lamp illumination were adopted to capture the wake flow behind a bluff obstacle. Among 200 effective particle s in two consecutive frames, 170 vectors were obtained averagely in the present study.

아로마 마사지가 림프부종에 미치는 영향 (Effects of Aromatherapy Massage on Edema Reduction in the Treatment of Lymphedema)

  • 김성중;심정묘;박용덕
    • 한국전문물리치료학회지
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    • 제14권3호
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    • pp.1-8
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    • 2007
  • The purpose of this study was to determine whether aromatherapy massages with manual lymph drainage (MLD) are significantly more effective than sham massages with MLD in reducing edematous limb volume in lymphedema. This study was performed on 46 patients who had developed unilateral upper or lower lymphedema. Twenty-three patients served as the experimental group and were treated with complex decongestive physiotherapy (CDP) applications including aroma massages with MLD, multi layered compression bandages, remedial exercises and skin care. Twenty-three patients in the control group were treated with CDP applications including sham massages with MLD, bandages, exercises and skin care. Patients undergo a therapy program once a day; 5 days a week for 2 weeks. Percentage excess volume (PEV) and body mass index (BMI) were recorded before and after treatment. PEV and BMI were significantly decreased before and after treatment in the experimental as well as in the control groups (p<.05). However, the percentage excess volume and BMI were not significantly improved after treatment between the two groups (p>.05). This study there suggests that aroma massages is not effective in the edema of patients with lymphedema.

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식이섬유, 효소 및 달걀 첨가 수준에 따른 쌀빵의 제빵 적성 및 품질 특성 (Characteristics of Bread-making and Quality of Rice Bread with Different Percentages of Dietary Fiber, Enzymes and Egg)

  • 김상숙;정혜영
    • 한국식생활문화학회지
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    • 제33권6호
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    • pp.580-587
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    • 2018
  • The baking properties of rice bread with polydextrose (3, 6, and 9%), enzymes (0.006, 0.009, and 0.018%) and egg (1.32 and 2.64%) were investigated. The specific gravity and color (L, a, b) of the dough, as well as the appearance, color (L, a, b) and texture of the rice bread were analyzed. The springiness, chewiness, gumminess (p<0.01) and hardness (p<0.001) of the rice bread tended to increase as the amount of added polydextrose increased. Replacement of rice flour with hemicellulase, glucose oxidase and fungal amylase are effective for producing rice bread. Replacement of rice flour with 0.009% glucose oxidase and 0.006% fungal amylase had a significant effect on increasing the volume and decreasing the hardness of the rice bread (p<0.001). Replacement of rice flour with 1.32% egg white also had a significant effect on increasing the volume and decreasing the hardness of the rice bread (p<0.001). These results suggest that replacement of rice flour with 0.009% glucose oxidase and 0.006% fungal amylase, and 1.32% egg white are effective for producing rice bread with good volume and hardness.