• Title/Summary/Keyword: Mesh Compression

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Development of Women's Cycle Wear Top with Improved Function (운동기능성 향상을 위한 여성용 사이클웨어 상의 개발)

  • Kwon, Chae-Ryung;Kim, Dong-Eun
    • Fashion & Textile Research Journal
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    • v.21 no.1
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    • pp.75-87
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    • 2019
  • The purpose of the study was to suggest a cycle wear top jersey improved in mobility. The study developed a new cycle wear with improvement in dissatisfaction factors by planning design, pattern and the functionality of fabric. Considering the amount of sweat and the necessities of compression part, the basic material, the additional compression material, and the mesh material were arranged differently according to areas. The assessment of the developed cycle wear was composed of wearing comfort evaluation by female cyclist, photo analysis and garment pressure evaluation. The developed cycle wear was evaluated and compared with the current cycle wear. As a result of wearing comfort evaluation, the developed cycle wear was evaluated as better than the existing ones in all part, particularly in the areas of reflection tape and materials, partial pressure, pocket size, and prevention of loss. Photo analysis was in agreement with the appearance evaluation of the participants. As a result of garment pressure evaluation, the front neck part was more comfortable and the upper arm, abdomen, and waist area showed higher pressure, so it partially supported the body. This study has significant meaning for developing a new cycle wear top, protecting the body and improving the exercise effect.

An Evaluation of Structural Performance of Reinforced Concrete Column Retrofitted with Grid Type Unit Details of Jacketing Method (격자형 유닛 상세를 가진 단면증설공법으로 보강된 철근콘크리트 기둥의 구조성능평가)

  • Moon, Hong Bi;Lee, Jeong In;Lee, Young Hak
    • Journal of Korean Association for Spatial Structures
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    • v.22 no.1
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    • pp.41-49
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    • 2022
  • In the case of columns in buildings with soft story, the concentration of stress due to the difference in stiffness can damage the columns. The irregularity of buildings including soft story requires retrofit because combined load of compression, bending, shear, and torsion acts on the structure. Concrete jacketing is advantageous in securing the strength and stiffness of existing members. However, the brittleness of concrete make it difficult to secure ductility to resist the large deformation, and the complicated construction process for integrity between the existing member and extended section reduces the constructability. In this study, two types of Steel Grid Reinforcement (SGR), which are Steel Wire Mesh (SWM) for integrity and Steel Fiber Non-Shrinkage Mortar (SFNM) for crack resistance are proposed. One reinforced concrete (RC) column with non-seismic details and two columns retrofitted with each different types of proposed method were manufactured. Seismic performance was analyzed for cyclic loading test in which a combined load of compression, bending, shear, and torsion was applied. As a result of the experiment, specimens retrofitted with proposed concrete jacketing method showed 862% of maximum load, 188% of maximum displacement and 1,324% of stiffness compared to non-retrofitted specimen.

Mechanical properties and damage constitutive model of self-compacting rubberized concrete

  • Ke, Xiaojun;Xiang, Wannian;Ye, Chunying
    • Computers and Concrete
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    • v.30 no.4
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    • pp.257-267
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    • 2022
  • Two different types of rubber aggregates (40 mesh rubber powder and 1-4 mm rubber particles respectively) were devised to substitute fine aggregates at 10%, 15%, 20% and 30% by volume in self-compacting concrete to investigate their basic mechanical properties. The results show that with the increase of rubber content, the reduction of compressive strength, splitting tensile strength and static modulus of elasticity gradually increase, and energy dissipation performance gradually increase. The rubber addition significantly reduces brittleness and decelerates damaged process. Whilst, the effect of rubber particles is greater when they are finer. Considering the mechanical properties, the optimal rubber content is 10%. It is recommended that the rubber volume content in rubberized concrete (RC) should not be higher than 20%. In addition, a constitutive model under uniaxial compression was proposed basing on the strain equivalent principle of Lemaitre and the damage theory, which was in good agreement with the test curves.

Efficient 3D Object Simplification Algorithm Using 2D Planar Sampling and Wavelet Transform (2D 평면 표본화와 웨이브릿 변환을 이용한 효율적인 3차원 객체 간소화 알고리즘)

  • 장명호;이행석;한규필;박양우
    • Journal of KIISE:Computer Systems and Theory
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    • v.31 no.5_6
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    • pp.297-304
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    • 2004
  • In this paper, a mesh simplification algorithm based on wavelet transform and 2D planar sampling is proposed for efficient handling of 3D objects in computer applications. Since 3D vertices are directly transformed with wavelets in conventional mesh compression and simplification algorithms, it is difficult to solve tiling optimization problems which reconnect vertices into faces in the synthesis stage highly demanding vertex connectivities. However, a 3D mesh is sampled onto 2D planes and 2D polygons on the planes are independently simplified in the proposed algorithm. Accordingly, the transform of 2D polygons is very tractable and their connection information Is replaced with a sequence of vertices. The vertex sequence of the 2D polygons on each plane is analyzed with wavelets and the transformed data are simplified by removing small wavelet coefficients which are not dominant in the subjective quality of its shape. Therefore, the proposed algorithm is able to change the mesh level-of-detail simply by controlling the distance of 2D sampling planes and the selective removal of wavelet coefficients. Experimental results show that the proposed algorithm is a simple and efficient simplification technique with less external distortion.

Study on the Linear Static Structural Analysis Error of Helical Compression Springs (압축 원통 코일 스프링의 선형 정적 구조 해석 오차에 관한 연구)

  • Jang, Sang Chan;Kang, Jung Ho
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.40 no.2
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    • pp.237-244
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    • 2016
  • Helical compression springs have been widely used in industries. The springs should be verified through experiment whether the inherent characteristics of the spring can be maintained during the manufacturing process. Considerable time and expense is spent in the manufacturing process. Therefore, in this study, the structural integrity evaluation of a spring was conducted using linear static structural analysis. Verification and comparison of the experimental data were carried out using a variety of international industrial standards with the intent to prove the validity of this study. The spring model did not consider coil ends. As a result of conducting the structural analysis, the quality of the mesh was improved and the time needed to create an analytical model was reduced. The study indicated that Poisson's ratio had little influence on the result of the structural analysis. Additionally, the possibility of verifying the structural integrity evaluation by structural analysis was confirmed.

Airway Stenting in Tracheobronchial Diseases : Silastic stenting (기도질환에서 실리콘 기도스텐트 치료)

  • Kim, Ho-Joong
    • Korean Journal of Bronchoesophagology
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    • v.10 no.2
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    • pp.5-8
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    • 2004
  • Stenosing airway disease is classified as intraluminal obstruction, extrinsic compression, and malacia by the anatomical site of the lesion. Stenting therapy is indicated for symptomatic relief of life-threatening dyspnea caused by the last two types. Airway stents are made with metal mesh and/or silicone rubber, and currently more than 20 kinds of stent are available. Among many kinds of silicone stent, the Dumon stent is mostly widely used for benign and malignant airway stenoses, but general anesthesia and rigid bronchoscopy are needed for insertion. It can be removed when the stenosing airway disease subsides completely. In many clinical studies, most patients $(85-90\%)$ improved immediately after stenting, and procedure-related mortality was low $(<3\%)$ in experienced centers. Stent displacement, mucus impaction, and granulation tissue formation are potential complications. Stenting is one of many effective therapeutic modalities for stenosing central airway disease. Careful patient selection, experiences, and continuous development of new technology will bring better results.

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Efficient 3D Mesh Sequence Compression Using a Spatial Layer Decomposition (공간 계층 분해를 이용한 효율적인 3 차원 메쉬 시퀀스 압축)

  • Ahn, Jae-Kyun;Kim, Chang-Su
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2013.06a
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    • pp.14-15
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    • 2013
  • 본 논문에서는 공간 계층 분해를 이용한 3 차원 메쉬 시퀀스 압축 기법을 제안한다. 제안하는 기법은 우선 각 점에 대한 시간적 궤적을 공분산 행렬로 표현하고, PCA(Principal component analysis)를 적용하여 시간 궤적에 대한 고유 벡터와 PCA 계수를 획득한다. 공간적인 예측을 통해 PCA 계수에 대한 벡터 차를 추출하고, 벡터 차와 그것에 대한 고유 벡터를 전송한다. 제안하는 방법은 PCA 계수 예측의 성능을 높이기 위해 점진적 압축에서 사용하는 공간 계층 분해 기법을 적용하여, 계수 예측에 효과적인 이웃 점을 지정하도록 한다. 또한, 이웃 점 개수를 사용자가 임의로 지정할 수 있도록 하여, 성능과 복잡도간의 트레이드 오프를 제어할 수 있도록 한다. 다양한 모델에 대한 실험 결과를 통해 제안하는 방법의 성능을 확인한다.

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Numerical study on concrete penetration/perforation under high velocity impact by ogive-nose steel projectile

  • Islam, Md. Jahidul;Liu, Zishun;Swaddiwudhipong, Somsak
    • Computers and Concrete
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    • v.8 no.1
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    • pp.111-123
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    • 2011
  • Severe element distortion problem is observed in finite element mesh while performing numerical simulations of high velocity steel projectiles penetration/perforation of concrete targets using finite element method (FEM). This problem of element distortion in Lagrangian formulation of FEM can be resolved by using element erosion methodology. Element erosion approach is applied in the finite element program by defining failure parameters as a condition for element elimination. In this study strain parameters for both compression and tension at failure are used as failure criteria. Since no direct method exists to determine these values, a calibration approach is used to establish suitable failure strain values while performing numerical simulations of ogive-nose steel projectile penetration/perforation into concrete target. A range of erosion parameters is suggested and adopted in concrete penetration/perforation tests to validate the suggested values. Good agreement between the numerical and field data is observed.

Finite Element Analysis of Seismic Isolation Bearing (면진베어링 유한요소해석)

  • Lee, Jae-Han;Yoo, Bong;Koo, Gyeong-Hoi
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1996.10a
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    • pp.45-51
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    • 1996
  • The combined shear and compression behaviors of seismic isolation rubber bearings are analyzed using the hyperelasticity material option of the ABAQUS computer program. The purpose of the analysis is to predict the behavior of laminated rubber bearing before the several tests. Some kinds of strain energy density functions are used as constitutive law for rubber itself having the hyperelasticity. The results are compared with test data peformed in Italy The analysis results show a little different with experimental results depending on the constitutive model and the refinement of finite element. The high order form of strain energy density functions results in good agreements and the mesh refinement above two for one rubber layer is enough to get good results.

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Development of finite element model using incremental endochronic theory for temperature sensitive material

  • Kerh, Tienfuan;Lin, Y.C.
    • Structural Engineering and Mechanics
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    • v.16 no.2
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    • pp.115-126
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    • 2003
  • A novel finite element model based on the incremental endochronic theory with the effect of temperature was developed in this study to explore the deformed behaviors of a flexible pavement material. Three mesh systems and two loading steps were used in the calculation process for a specimen of three-dimensional circular cylinder. Computational results in the case of an uni-axial compression test for temperatures at $20^{\circ}C$ and at $40^{\circ}C$ were compared with available experimental measurements to verify the ability of developing numerical scheme. The isotropic response and the deviatoric response due to the thermal effect were presented from deformations in different profiles and displacement plots for the entire specimen. The characteristics of changing asphalt concrete material under a specified loading condition might be seen clearly from the numerical results, and might provide an useful information in the field of road engineering.