• Title, Summary, Keyword: 체적비

Search Result 1,184, Processing Time 0.047 seconds

Volume Calculation Using Stereo Camera and Non-uniform Mesh (스테레오 카메라와 비균일 메시를 이용한 체적 계산 알고리즘)

  • Lee, Young-Dae;Cho, Sung-Yun
    • Proceedings of the Korean Society of Computer Information Conference
    • /
    • /
    • pp.429-432
    • /
    • 2012
  • In this paper, we proposed the algorithm computes the waste volume periodically for the way of waste repository standard. For the construction of safe and clear urban environment, it is necessary that we identify the rubbish waste volume and we know the accuracy volume. After camera calibration, we obtained the point cloud on the surface of the object and took this as the input of the calculation algorithm of the object volume. We proposed the two volume calculation algorithms based on the triangularmeshing methods and verified the validity of the algorithm through simulation and real experiments. The proposed algorithm can be used not only as the volume calculation of the waste repository but also as the general volume calculation of a three dimensional object.

  • PDF

On Overtopping Characteristics of Tsunami due to Waveforms (파형에 따른 지진해일의 월파특성에 관한 고찰)

  • Lee, Woo-Dong;Kim, Jung-Ouk;Park, Jong-Ryul;Hur, Dong-Soo
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • /
    • pp.142-146
    • /
    • 2017
  • 지진해일의 수리특성을 분석하기 위하여 유사한 파형특성을 가진 고립파를 많이 이용하고 있다. 그러나 고립파의 근사파형은 실제 지진해일에 비해 상당히 좁은 파형분포를 가지고 있다. 이에 수치모의에서는 기존의 고립파 근사식을 개량하여 고립파형의 지진해일을 수치적으로 생성하고 있다. 본 연구에서는 지진해일의 파형분포에 따른 월파특성을 수치적으로 조사하기 위하여 개량된 고립파 근사식을 2차원 N-S solver에서 적용하였다. 이것에 기초하여 수치파동수조에 직립호안과 그 배후에는 월파수조를 설치하고, 지진해일 월파량을 측정하였다. 수치해석결과로부터 직립호안 주변의 공간파형과 마루 위의 유속분포로부터 파형분포에 따른 월파현상을 분석할 수 있었다. 또한 기존 고립파 근사이론 대비 개량된 고립파의 체적비에 따른 월파량 변화를 정량적으로 조사하였다. 그 결과 지진해일의 체적비가 증가할수록 월파량이 거의 선형적으로 증가하는 경향을 나타내었다.

  • PDF

Failure Analysis of RC Cylindrical Structures using Layered Shell Element with a Pressure Node (압력절점을 갖는 적층쉘 요소에 의한 콘크리트 원통형 구조물의 파괴해석)

  • 송하원;방정용;변근주;최강룡
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.12 no.3
    • /
    • pp.475-484
    • /
    • 1999
  • 압력절점은 요소의 균등한 압력증분을 1개의 자유도로 갖는 절점이며, 유한요소의 하중-변위 평형방정식에 체적과 압력의 관계를 추가하여 한계압력 이후에서도 체적변화에 따른 압력증분을 직접적으로 제저할 수 있는 절점이다. 본 연구에서는 철근콘크리트의 평면 구성 방정식과 적층정식화에 적용한 쉘 요소에 압력절점을 추가하고 해석시 체적을 제어함으로써 철근콘크리트 원통형 구조에 대해 파괴까지의 극한내압 능력을 해석할 수 있는 체적제어 비선형 해석기법을 개발하였다. 본 논문에서 제안한 해석기법을 이용하여 철근콘크리트 원통형 구조물에 대하여 비선형 해석을 수행하여 한계압력과 한계압력 이후의 구조물의 거동을 예측하였으며 실험결과와 비교 검증하였다.

  • PDF

Development and Application of TDR Penetrometer for Evaluation of Soil Water Content of Subsoil (지반의 함수비 평가를 위한 관입형 TDR 프로브의 개발 및 적용)

  • Hong, Won-Taek;Jung, Young-Seok;Lee, Jong-Sub;Byun, Yong-Hoon
    • Journal of the Korean Geotechnical Society
    • /
    • v.31 no.2
    • /
    • pp.39-46
    • /
    • 2015
  • Dielectric constant depends on the variation of soil water content, and the estimation of soil water content using time domain reflectometry (TDR) has been studied by many researchers. The purpose of this study is the development and application of TDR penetrometer (TDRP) in order to evaluate the soil water content according to the penetration depth. The TDRP consists of cone, sleeve, driving rod, hammer, and guide. Three electrodes, which are used to measure the dielectric constant of soils, are mounted on the surface of sleeve and, in turn, connected with coaxial cable and time domain reflectometer. To establish the relationship between the volumetric water content and dielectric constant, several laboratory tests by using the TDRP are performed in the specimens with a variety of volumetric water content. The experimental results show that the dielectric constant is strongly correlated to volumetric water content as polynomial equations with an order of 3. In addition, the volumetric water content calculated from the dielectric constant is similar to that obtained from the sample weight. In the field, a small sampler is used to compare the volumetric water content calculated from the dielectric constant with the volumetric water content obtained from the sample. The results of field application demonstrate that the volumetric water content estimated by the TDRP shows similar trend to the gravimetric water content of sample. This study suggests that the TDRP is effectively used to evaluate the volumetric water content of unsaturated soils according to the penetration depth.

Seismic Behavior of High-Strength Reinforced Concrete Bridge Columns (고강도 철근콘크리트 교각의 내진 거동)

  • Hwang Sun-Kyoung;Lee Chin-Ok;Ryu Hyo-Jin;Yun Hyun-Do;Lim Byung-Hoon
    • Journal of the Korea Concrete Institute
    • /
    • v.17 no.4
    • /
    • pp.505-511
    • /
    • 2005
  • This experimental investigation was conducted to examine the seismic performance of reinforced concrete bridge columns. The columns were subjected to a constant axial load and a cyclic horizontal load-inducing reversed bending moment. The variables studied in this research were the volumetric ratios of transverse reinforcement (ps=0.96, 1.44 percent) and axial load ratios (P/Po=0.05, 0.1, 0.2) and concrete strengths (35, 60MPa). Test results showed that bridge columns with $44\%$ higher amounts of transverse reinforcement than that required by seismic provisions of ACI 318-02 showed ductile behavior. For bridge columns with axial load ratio(P/Po) less than 0.2, the ratio of $M_{max}\;over\;M_{ACI}$, nominal moment capacity predicted by ACI 318-02 provisions, was consistently greater than 1 with approximately a $20\%$ margin of safety.

비배수 지하굴착의 거동에 관한 수치해석적 방법

  • 이승래
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • /
    • pp.1.1-10
    • /
    • 1989
  • 본 연구에서는 유효응력 개념에 기초를 둔 응력-변형을 관계식을 이용하여 비배수 지하굴착 거등을 모댈하기 위한 수치해석적 방법이 개발된다. 비배수 조건 시 적용되는 체적불변형 조건은 조건방정식(Penalty formulation)의 혁태로 공극수압 변수를 이용하여 주어지며 결과되는 유한요소 방정식에 상닻히 른 물외 체적변형 개수를 부여함으로서 이루어진다. 이러한 형태와 조건식은 지하굴착 과정에서 발생되는 비배수 공극수압의 계산을 가능케 한다. 체적불변형 조건 부여 시 발생되는 mesh locking은 그 결과에 상당한 영향을 미치므로 이러한 mesh locking 문제는 T-방법에 근거를 둔 salective 적분방법월 적용함으로서 해결될 수 있다. 또한 흙의 거등을 모델하기 위하여 사용 된 Cam-Clay모텔과 Drucker-prager모텔에 새로운 implicit 웅력적분 방법을 적용함으로서 효율적인 방법으로 비선형거동을 해석할 수 있다. 개발된 지하 굴착 해석방법의 적용성을 검증하기 위하여 실재 현장에서 측정된 지하굴착 거동을 예제로 이용하였다.

  • PDF

The Efficacy of the Change in Belly Board Aperture Location by the Addition of Bladder Compression Device for Radiotherapy of Rectal Cancer (직장암 환자의 골반 방사선치료에서 벨리보드 하위 경계 위치 변화의 영향)

  • Yoon, Hong-In;Chung, Yoon-Sun;Kim, Joo-Ho;Park, Hyo-Kuk;Lee, Sang-Kyu;Kim, Young-Suk;Choi, Yun-Seon;Kim, Mi-Sun;Lee, Ha-Yoon;Chang, Jee-Suk;Cha, Hye-Jung;Seong, Jin-Sil;Keum, Ki-Chang;Koom, Woong-Sub
    • Radiation Oncology Journal
    • /
    • v.28 no.4
    • /
    • pp.231-237
    • /
    • 2010
  • Purpose: We investigated the effect of location changes in the inferior border of the belly board (BB) aperture by adding a bladder compression device (BCD). Materials and Methods: We respectively reviewed data from 10 rectal cancer patients with a median age 64 years (range, 45~75) and who underwent computed tomography (CT) simulation with the use of BB to receive pelvic radiotherapy between May and September 2010. A CT simulation was again performed with the addition of BCD since small bowel (SB) within the irradiated volume limited boost irradiation of 5.4 Gy using the cone down technique after 45 Gy. The addition of BCD made the inferior border of BB move from symphysis pubis to the lumbosacral junction (LSJ). Results: Following the addition of BCD, the irradiated volumes of SB and the abdominopelvic cavity (APC) significantly decreased ($174.3{\pm}89.5mL$ vs. $373.3{\pm}145.0mL$, p=0.001, $1282.6{\pm}218.7mL$ vs. $1,571.9{\pm}158mL$, p<0.001, respectively). Bladder volume within the treated volume increased with BCD ($222.9{\pm}117.9mL$ vs. $153.7{\pm}95.5mL$, p<0.001). The ratio of irradiated bladder volume to APC volume with BCD ($33.5{\pm}14.7%$) increased considerably compared to patients without a BCD ($27.5{\pm}13.1%$) (p<0.001), and the ratio of irradiated SB to APC volume decreased significantly with BCD ($13.9{\pm}7.6%$ vs. $24.2{\pm}10.2%$, p<0.001). The ratios of the irradiated SB volume and irradiated bladder volume to APC volume negatively correlated (p=0.001). Conclusion: This study demonstrated that the addition of BCD, which made the inferior border of BB move up to the LSJ, increased the ratio of the bladder to APC volume and as a result, decreased the irradiated volume of SB.

Primary study on evaluation of wetting front distribution for weathered soil (토층 사면에서의 침윤선 분포 특성 파악을 위한 실험 연구)

  • Kim, Man-Il;Chae, Byung-Gon;Seo, Yong-Seok;Kim, Hyeun
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • /
    • pp.1395-1399
    • /
    • 2008
  • 국내 토층 사면을 대상으로 강우에 의해 발생되는 침투수 거동 특성을 분석함으로써 지속적인 토층의 물성 변화 계측을 통해 산사태 예 경보시스템을 구축이 가능하다. 본 연구에서는 산사태 예 경보시스템 구축의 사전 단계로써, 국내 대표적인 지질 매질인 화강암 풍화토, 편마암 풍화토와 주문진 표준사에 대해 공극률과 체적함수비 등의 토질 물성 변화를 고려한 실내 보정실험을 수행하였다. 실험조건은 공극률, 체적함수비 변화에 대한 측정센서의 측정 정밀도 향상과 이를 통해 국내 현장토에 대한 고유 보정기법을 제시하기 위함이다. 측정센서는 각 실험 조건별 물성 변화에 따라 전압을 측정함으로써 현장토에 대한 물성치와 상호 분석이 가능하도록 하였다. 주문진 표준사 뿐만 아니라 국내 현장토인 화강암 풍화토와 편마암 풍화토에 대한 체적함수비에 대한 보정식도 함께 제시하였다.

  • PDF

Mechanical Properties and Fracture Behavior of Cylindrical Shell Type for Unidirectional CFRP Composite Material under Tension Load (원통형 셀 구조를 갖는 한방향 CFRP 적층 복합재료의 정적인장파괴거동)

  • 오환섭
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
    • /
    • /
    • pp.273-278
    • /
    • 1998
  • In this paper, basic micro-mechanical properties of unidirectional CFRP composite shell such as bonding strength, fiber volume fraction and void fraction are measured and tensile strength test is performed with a fixture. And then fracture surfaces are observed by SEM. In case of basic micro-mechanical properties, bonding strength is reduce with decreasing of radius of each ply in a shell for the effect of residual stress, fiber volume fraction is smaller than plate, and void fraction is vise versa. For these reason, tensile strength of shell is smaller than plate fabricated with same prepreg. For failure mode shell has many splitted part along its length, and it is assumed that this phenomenon is caused by the difference of bonding strength for residual stress.

  • PDF

A Study on the Flow Characteristics and Pressure Loss of a Muffler for the Variation of Volumetric Rate and Offset (체적비와 오프셋 변화에 의한 소음기내의 유동특성과 압력손실에 관한 연구)

  • 김민호;정우인;천인범
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.8 no.4
    • /
    • pp.93-99
    • /
    • 2000
  • It is well known that an automotive muffle strongly influences engine efficiency and noise reduction. The performance of a muffler system is determined by the geometrical parameters such as the relative location of an inlet and outlet pipe size and cross sectional geometry of a chamber. In this study numerical analysis was performed to examine the flow characteristics in the simple automotive muffler for the variation of volumetric rate and offset. The computational grid generation was carried out. The RNG k-$\varepsilon$ turbulence model was applied. To provide the boundary condition for numerical analysis the experimental measurement wes carried out. As a result of this study we could understand that there was a recirculation flow inside muffler and pressure loss depends on the variation of volumetric rate and offset.

  • PDF