• Title/Summary/Keyword: Shape understanding

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A Study on Noise Identification of Indoor Air-conditioner Using Experimental Methods (실험적 방법을 통한 에어컨 실내기의 소음원 검출에 관한 연구)

  • 이성진;오재응;이정윤;강태호
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.05a
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    • pp.87-87
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    • 2004
  • An air-conditioner has various noise sources such as a fan noise, a motor noise, and a vibration induced noise. To reduce these noise effectively, noise sources must be identified. Especially in this paper, the structure borne sound radiated from the motor bracket of the indoor air-conditioner is considered. To do this, the operational deflection shape, which is used for understanding of the behavior of the motor bracket at a particular frequency, is obtained and compared with the sound intensity, which is used for the noise identification. Through this study, the noise sources of indoor air-conditioner are defined and the effective noise reduction method is proposed.

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Identification of the three-dimensional topology of hairpin packet structures in turbulent boundary layers (난류경계층의 헤어핀 다발구조에 대한 3차원 토폴로지 규명)

  • Kwon, Seong-Hoon;Kim, Kyung-Chun
    • Proceedings of the KSME Conference
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    • 2003.11a
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    • pp.610-615
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    • 2003
  • This experiment has been carried out to find the structure of turbulent boundary layer with instantaneous velocity fields obtained in stream-wall-normal planes using a stereo-PIV (Particle Image Velocimetry) method. And it has been measured perpendicular plane and horizontal plane with hairpin vortex structure by Reynolds number change and made third dimension shape for section of horizontal plane through stereo-PIV. In the outer layer hairpin vortices occur in streamwise-aligned packets that propagate with small velocity dispersion. A streaky structure is composed of counter-rotating vortex. According as y+ increases, streaky structure's interval space decrease, and it shows that hairpin shape of prior research is vertified. The objective of the present research is to gain a better understanding of coherent structures in the outer of wall turbulence by experimentally examining coherent structures.

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AUTOMATIC BUILDING EXTRACTION BASED ON MULTI-SOURCE DATA FUSION

  • Lu, Yi Hui;Trinder, John
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.248-250
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    • 2003
  • An automatic approach and strategy for extracting building information from aerial images using combined image analysis and interpretation techniques is described in this paper. A dense DSM is obtained by stereo image matching. Multi-band classification, DSM, texture segmentation and Normalised Difference Vegetation Index (NDVI) are used to reveal building interest areas. Then, based on the derived approximate building areas, a shape modelling algorithm based on the level set formulation of curve and surface motion has been used to precisely delineate the building boundaries. Data fusion, based on the Dempster-Shafer technique, is used to interpret simultaneously knowledge from several data sources of the same region, to find the intersection of propositions on extracted information derived from several datasets, together with their associated probabilities. A number of test areas, which include buildings with different sizes, shape and roof colour have been investigated. The tests are encouraging and demonstrate that the system is effective for building extraction, and the determination of more accurate elevations of the terrain surface.

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Experimental and Numerical Study of Cold Ironing as a Post-Process of Net-Shape Manufacture of Gears (기어 정밀정형 성형을 위한 후 공정으로서의 냉간 아이어닝 공정에 대한 연구)

  • Chang, Yu-Chul;Park, Chul-Sung;Kim, Byung-Min;T.A. Dean;Kang, Beom-Soo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.10
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    • pp.2096-2103
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    • 2002
  • Cold ironing, as a post-forging operation of warm forged gears, needs a clear understanding of form errors due to die-elasticity and springback of component. In order to simplify the analysis of cold ironing, a single tooth instead of a whole gear component was investigated. The influence of initial surface roughness, die design, and die/workpiece interference has been examined experimentally and numerically. As a result the changes in geometrical profile, dimensions, and surface finish in a single tooth were observed. This study demonstrates that predicted dimensions can be achieved and surface finish also can be greatly improved.

Study on small resistance regions in post-liquefaction shear deformation based on soil's compressive properties

  • Jongkwan Kim;Jin-Tae Han;Mintaek Yoo
    • Geomechanics and Engineering
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    • v.36 no.3
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    • pp.295-301
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    • 2024
  • Understanding the post-liquefaction shear behavior is crucial for predicting and assessing the damage, such as lateral flow, caused by liquefaction. Most studies have focused on the behavior until liquefaction occurs. In this study, we performed undrained multi-stage tests on clean sand, sand-silt mixtures, and silty soils to investigate post-liquefaction shear strain based on soil compressibility. The results confirmed that it is necessary to consider the soil compressibility and the shape of soil particles to understand the post-liquefaction shear strain characteristics. Based on this, an index reflecting soil compressibility and particle shape was derived, and the results showed a high correlation with post-liquefaction small resistance characteristic regardless of soil type and fine particle content.

Design Factor and Formative Characteristic on Korean Aesthetic in Fashion (패션에 나타난 한국미의 조형성과 디자인 요소)

  • Ryu, Hyun-Jung
    • Journal of the Korea Fashion and Costume Design Association
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    • v.12 no.1
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    • pp.51-59
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    • 2010
  • The purpose of this study is to help understanding of Korean fashion image by studying of design factor and formative characteristic. The methods of this study are the study of academic literatures as well as practical study through the analysis of case studies about actual works. The summary of this study's results is like followings. First, Perspectives seeing formative characteristic on Korean fashion image are Shape with a line, color, material, pattern, accessories. Second, Design factors deciding Korean fashion image are pattern, then in order of shape, color, material, accessories. Third, In results on design factor deciding Korean fashion image, when fashion designers focus on pattern, pattern is focused on without regard for other design factor. But color and material are accompanied by other design factor in expressing Korean fashion image. As fashion design point expressing Korean astetic, use of pattern is minimized other design factor, color and material are used with other design factor, then Korean fashion image will come out more than other time else. If We develop Korean fashion design to concentrate on shape and pattern, Korean fashion culture will be known to world people and beautiful value of Korean fashion will be handed effectively.

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A Study on Design Methods and the Composition Elements in Flexure Structure Systems (휨 구조시스템의 구조디자인적 구성요소와 디자인 조합 수법 분석)

  • Lee, Juna
    • Journal of Korean Association for Spatial Structures
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    • v.16 no.1
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    • pp.73-84
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    • 2016
  • This study analyzes the four composition elements : profile, anchorage and connection, material and member rigidity, stability, as the main composition design elements of flexure structure systems, in order to explore possibilities for more various structure designs in architectures with flexure structure system. It also examines typical design methods that use the mentioned four composition elements. At the results, this research presents an understanding of the differences between funicular shape and non-funicular shape and mechanical features of the shapes in the profile element, regarding to the ratio of rise height to span length(f/l). Also, the typical design methods are presented for the designable usages of the hinge joints and the fix joints, and for the applications of member rigidity expressed by the index of the ratio of member depth to span length(d/l). And it was presented that connection styles, addition of brace members, placement of shear walls are the main design methods in the stability element. This data would be useful to architectural designs concerning integrated design with structures.

Development of Rich Internet Application in the Three-Dimensional Shapes of Elementary Mathematics (초등학교 수학과 입체도형 영역의 학습 RIA 개발)

  • Kim, Kap-Su;You, Tae-Ho
    • Journal of The Korean Association of Information Education
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    • v.12 no.4
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    • pp.395-404
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    • 2008
  • The shape learning of elementary mathematics should required a variety of activities to help student based on intuitive understanding. Learning three-dimensional shapes, it is effectively take advantage of actual object, but difficult to check a development figure or various forms of actual object, it is effectively utilizing computers semi-actual object. In addition, the computer to take advantage of even after school resources, the limits of learning something concrete to take advantage complement. This research developed the three-dimensional shapes application of elementary students shape learning to use of Flex and Flash. This application to take advantage of the free observation and causing an interesting and effective learning.

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Effect of Random Geometry Perturbation on Acoustic Scattering (기하형상의 임의교란이 음향산란에 미치는 영향)

  • 주관정
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1992.10a
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    • pp.117-123
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    • 1992
  • In recent years, the finite element method has become one of the most popular numerical technique for obtaining solutions of engineering science problems. However, there exist various uncertainties in modeling the problems, such as the dimensions(geometry shape), the material properties, boundary conditions, etc. The consideration for the uncertainties inherent in the problems can be made by understanding the influences of uncertain parameters[1]. Determining the influences of uncertainties as statistical quantities using the standard finite element method requires enormous computing time, while the probabilistic finite element method is realized as an efficient scheme[2,3] yielding statistical solution with just a few direct computations. In this paper, a formulation of the probabilistic fluid-structure interaction problem accounting for the first order perturbation of geometric shape is derived, and especially probabilistical acoustic pressure scattering from the structure with surrounding fluid is focused on. In Section 2, governing equations for the fluid-structure problems are given. In Section 3, a finite element formulation, based on the functional, is presented. First order perturbation of geometric shape with randomness is incorporated into the finite element formulation in conjunction with discretization of the random fields in Section 4 and 5. Finally, the proposed formulation is applied to a acoustic pressure scattering problem from an infinitely long cylindrical shell structure with randomness of radial perturbation.

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The Appraisal of Female Jackets from the Period of $1890s{\sim}1960s$ (1890년${\sim}$1960년대 여자 저고리 감정)

  • Choi, Eun-Soo
    • Journal of the Korean Society of Costume
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    • v.58 no.5
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    • pp.178-197
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    • 2008
  • Due to the inflow of the western culture since the 19th century, female skirts and jackets have been changed considerably in detail though their basic composition was maintained. The analysis on female jackets from the start of the modern period to 1960s has been undertaken with artefacts as well as reports and research dissertations related to them. For period appraisal, analysis was divided into several periods which are from 1890s to 1910s, and every 10 years afterwards. As a result, aspects for the appraisal in each period was found. Aspects for period appraisal in modern jackets can be a change in total length and side length, a change in shape of the sleeves (from straight to round), a change in width, and a difference in closed shape of the collars. Material and color can be another aspect which shows fashionable material or new materials (man-made textile or nylon) of each period, color combination of surface and lining material as well as other parts of the jacket, use of a stiffener made with net or sheer textiles. Research using books and archives is important for the appraisal of the garment artifact. However, most of all, one should have the attitude of examining the artifacts frequently in order to achieve deeper understanding and an eye for accurate appraisal.