• Title/Summary/Keyword: geometric cut

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Model Development of Flexible Disk Grinding Process

  • Yoo, Song-Min;Choi, Myung-Jin;Kim, Young-Jin
    • Journal of Mechanical Science and Technology
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    • v.14 no.10
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    • pp.1114-1121
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    • 2000
  • A flexible disk grinding process model was developed based on the dynamic relationship proposed by Kurfess and the influence of the major system parameters which potentially affect the grinding process was studied. Due to the process complexities, several new parameters were assumed to be kinematically dependent on the geometric layouts of the process. Different process stages had been defined depending on the kinematic relationships between the grinding disk and workpiece. A trend of depth of cut was simulated using the proposed model and compared with the empirically measured data in two dimensions. Due to a poor prediction capability of the first model, a modified model was proposed and a better performance has been proved to reveal a closer description of processed surface quality. Also a deflection length has been verified using a different analytical approach.

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Research on the Multi-Focus Image Fusion Method Based on the Lifting Stationary Wavelet Transform

  • Hu, Kaiqun;Feng, Xin
    • Journal of Information Processing Systems
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    • v.14 no.5
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    • pp.1293-1300
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    • 2018
  • For the disadvantages of multi-scale geometric analysis methods such as loss of definition and complex selection of rules in image fusion, an improved multi-focus image fusion method is proposed. First, the initial fused image is quickly obtained based on the lifting stationary wavelet transform, and a simple normalized cut is performed on the initial fused image to obtain different segmented regions. Then, the original image is subjected to NSCT transformation and the absolute value of the high frequency component coefficient in each segmented region is calculated. At last, the region with the largest absolute value is selected as the postfusion region, and the fused multi-focus image is obtained by traversing each segment region. Numerical experiments show that the proposed algorithm can not only simplify the selection of fusion rules, but also overcome loss of definition and has validity.

A Study on the Characteristics of Geometry in Madeleine Vionnet´s Works (마들렌느 비오네의 작품에 나타난 기하학적 특성에 관한 연구)

  • 유수경;김의경
    • The Research Journal of the Costume Culture
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    • v.10 no.6
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    • pp.763-780
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    • 2002
  • The aim of this research is to analyze Vionnet´s geometric features, which can be regarded as the key formative beauty among the external characteristics of her works. and to thereby establish the theory that her works emitted a time-transcending life force because they were patterns designed based on a geometrical frame of mind. To prove such argument, studies to understand the basic geometrical aspects appearing in her works will be made by taking a look at the general features of geometry, viewing Vionnet´s philosophy for designing, and examining the geometric cutting methods. The period covered in this paper will center mainly on dresses Vionnet made from her very active days in the fashion sector, 1919. till when she retired from the fashion industry, around 1939. What's outstanding about Vionnet´s geometric principle expressed in her works is the unique cutting method that acknowledges the silhouette of the human body as a cubic or three-dimensions concept, through insight of the human body, the mechanics of the materials, and geometry. Vionnet introduced a simple and elegant design by combining geometric figure cuts, such as rectan히es. quadrants, and triangles. Moreover, she created a new sewing structure that plans everything about the materials to the tiniest detail, resulting in producing a softer style With this, Vionnet showed the geometrical correlation can bring about harmony and the beauty of ideal proportion, forming the source of eternal beauty. As discussed so fu, the geometrical characteristics appearing in Vionnet´s works are marked such as spirals, zig-zag lines, asymmetries. panels, gradation, golden proportion, and the mobius-band.

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Effect on Axial Rake Angle of Cutting Edge for Machinable Ceramics (절삭 선단의 축 방향 경사각이 가공성 세라믹에 미치는 영향)

  • Jang, Sung-Min;Yun, Yeo-Kwon
    • Journal of the Korean Society of Safety
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    • v.24 no.2
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    • pp.7-12
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    • 2009
  • The machining process of ceramics can be characterized by cracking and brittle fracture. In the machining of ceramics, edge chipping and crack propagation are the principal reasons to cause surface integrity deterioration. Such phenomenon can cause not only poor dimensional and geometric accuracy, but also possible failure of the ceramic parts. Thus, traditional ceramics are very difficult-to-cut materials. Generally, ceramics are machined using conventional method such as grinding and polishing. However these processes are generally costly and have low MRR(material removal rate). To overcome such problems, in this paper, h-BN powder, which gives good cutting property, is added for the fabrication of machinable ceramics by volume of 10 and 15%. The purpose of this study is an analysis of endmill's rake angle for appropriate tools design and manufacturing for the machinable ceramics. In this study, Experimental works are executed to measure cutting force, surface roughness, tool fracture, on different axial rake angle of endmills. Cutting parameters, namely, feed, cutting speed and depth of cut are used to accomplish purpose of this paper. Required experiments are performed, and the results are investigated.

A Study on Tooth Profile Error in Internal Gear Shaping (내치차 절삭시의 치형오차에 관한 연구)

  • 박천경;최영석
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.15 no.1
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    • pp.154-162
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    • 1991
  • In this study, the simulation program is developed where the tooth profile error in internal gear shaping is calculated considering several factors which affect it. This factors are the circular feed of the pinion cutter, the interference by the geometric conditions of the cutter and the internal gear, the deviation from the theoretical involute profile of the cutter and the eccentricity of the cutter and the internal gear. With this program, the effects are investigated which the geometric conditions and the cutting conditions in internal gear shaping have on the tooth profile error of the internal gear. The condition for the minimization of it is derived and then the results of simulation are adequately verified by measurements of internal gears cut by a pinion cutter.

A Study on Formative Characteristics of the Leggings Design in Contemporary Fashion (현대패션에 나타난 레깅스 디자인의 조형적 특성 연구)

  • Hwang, You Jung;Choi, Jung Hwa
    • Fashion & Textile Research Journal
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    • v.16 no.1
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    • pp.1-12
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    • 2014
  • Leggings are recognized as unique fashion items that meet the needs of customers to express individuality due to their protective and thermal functions. They are highly practical fashion items that show a casual, street and sportive style with a noted influence on outdoor leisure fields. This study analyzes the sociocultural background for the spread of leggings as well as their design characteristics, coordination characteristics and authentic characteristics. The formative characteristics of modern legging designs are as follows. First, the shapes of modern leggings are ankle-length, calflength, above-knee, knee-length, stirrup and top of the foot-length. Leggings are transformed in many ways: length-expansion, side-slit, unbalanced length, variations of straps, cut-out, trimmings, pattern transformation and complex form. Second, modern leggings contain achromatic colors in modern and sensual image, vivid colors in sportive image and metallic colors futuristic and technical image. Third, leggings patterns value originality, uniqueness and rarity as shown by printed geometric patterns, hand crafted geometric and natural patterns, and abstract patterns expressed through various materials and themes. Fourth, modern leggings' textures are categorized into erotic, simply-functional, seasonless, glossy, and metallic. Functional and fashionable leggings reflect the psychological needs of modern society. This study suggests a direction for the development of legging designs and provides a theoretical database for higher value-added leggings business.

Surface Properties and Tool Wear of Si3n4-hBN Machinable Ceramics in Endmill Machining using Tungsten Carbide Tool (텅스텐 카바이드 공구를 사용한 앤드밀 가공에서 Si3n4-hBN 머시너블 세라믹스의 표면특성과 공구마멸)

  • Jang, Sung-Min;Cho, Myeong-Woo
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.3 no.1
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    • pp.15-21
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    • 2004
  • The machining process of ceramics can be characterized by cracking and brittle fracture. In the machining of ceramics, edge chipping and crack propagation are the principal reasons to cause surface integrity deterioration. Such phenomenon can cause not only poor dimensional and geometric accuracy, but also possible failure of the ceramic parts. Thus, traditional ceramics are very difficult-to-cut materials. To overcome such problems, in this paper, h-BN powder, which gives good cutting property, is added for the fabrication of machinable ceramics by volume of 5, 10, 15, 20, 25 and 30%. The objectives of this paper is to evaluate the fracture phenomenon of the tungsten carbide tool and the variation of surface integrity of the manufactured machinable ceramics under various cutting conditions during end mill machining With CNC machining center.

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Design Optimization of A Multi-Blade Centrifugal Fan With Variable Design Flow Rate (설계유량을 변수로 한 원심다익송풍기의 최적설계)

  • Seo, Seung-Jin;Kim, Kwang-Yong
    • Proceedings of the KSME Conference
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    • 2004.04a
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    • pp.1726-1731
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    • 2004
  • This paper presents the response surface optimization method using three-dimensional Navier-Stokes analysis to optimize the shape of a forward-curved blades centrifugal fan. For numerical analysis, Reynolds-averaged Navier-Stokes equations with $k-{\varepsilon}$ turbulence model are discretized with finite volume approximations. In order to reduce huge computing time due to a large number of blades in forward-curved blades centrifugal fan, the flow inside of the fan is regarded as steady flow by introducing the impeller force models. Three geometric variables, i.e., location of cut off, radius of cut off, and width of impeller, and one operating variable, i.e., flow rate, were selected as design variables. As a main result of the optimization, the efficiency was successfully improved. And, optimum design flow rate was found by using flow rate as one of design variables. It was found that the optimization process provides reliable design of this kind of fans with reasonable computing time.

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Design Optimization of A Multi-Blade Centrifugal Fan With Variable Design Flow Rate (설계유량을 변수로 한 원심다익송풍기의 최적설계)

  • Seo, Seoung-Jin;Kim, Kwang-Yong
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.28 no.11
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    • pp.1332-1338
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    • 2004
  • This paper presents the response surface optimization method using three-dimensional Navier-Stokes analysis to optimize the shape of a forward-curved blades centrifugal fan. For numerical analysis, Reynolds-averaged Navier-Stokes equations with k-$\varepsilon$ turbulence model are discretized with finite volume approximations. In order to reduce huge computing time due to a large number of blades in forward-curved blades centrifugal fan, the flow inside of the fan is regarded as steady flow by introducing the impeller force models. Three geometric variables, i.e., location of cut off, radius of cut off, and width of impeller, and one operating variable, i.e., flow rate, were selected as design variables. As a main result of the optimization, the efficiency was successfully improved. And, optimum design flow rate was found by using flow rate as one of design variables. It was found that the optimization process provides reliable design of this kind of fans with reasonable computing time.

A Study on the Japanese Traditional Borrowed Landscape in Architecture of Ando Tadao -Focusing on his concept by 'polymerization of abstraction and representation'- (안도다다오 건축에 표현된 일본전통 차경기법에 관한 연구 -그의 '추상과 구상의 중합'에 의한 개념을 중심으로-)

  • Han, Myoung-Sik
    • Korean Institute of Interior Design Journal
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    • v.17 no.1
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    • pp.30-38
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    • 2008
  • Borrowed landscape is an Oriental gardening method to draw inside external natural landscape, and borrowed landscape of Japan has a different characteristic from that of Korea or China nature is manipulated and re-interpreted by human will in the course of applying it to architectural space. In other words, not the original scenery, but manipulated one appears which is cut, reduced, or deleted by architectural elements such as wall, window, or fence. Therefore, this study examined how architectural structure of Ando Tadao symbolizing modernist architecture understood and adopted Japanese traditional views on nature, that is, borrowed landscape. To this end, on the basis of the understanding on 'polymerization of abstraction and form' he mentioned, his geometric architectural principles are discussed, since this serves to be an important beginning of architectural concretization by the concept of 'form' experienced and perceived by human being through geometric means called architecture 'abstraction.' The findings of this study are as follows: first, it was found that Ando Tadao generates borrowed landscape effects by polymerizing and manipulating his simple and geometric structures with each other and thereby editing natural scenery, while Japanese traditional borrowed landscape introduces source scenery inside, through condensation and symbolization. Second, the results of this study revealed that his architecture functions to transcend external and internal realm of a space, which is also observed in Japanese traditional architectural borrowed landscape. Therefore, this study is considered significant in the sense that it proved that Ando Tadao's architectural language is based on borrowed landscape as a specific Japanese traditional element, going beyond the scope of previous studies focusing simply on the introduction of natural elements.