• Title/Summary/Keyword: shape properties

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A Study on the Learning Shape Knowledge and Design with Inductive Generalization (귀납적 일반화를 이용한 형태지식의 습득과 디자인에 관한 연구)

  • Cha, Myung-Yeol
    • Korean Institute of Interior Design Journal
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    • v.19 no.6
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    • pp.20-29
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    • 2010
  • Art historians and critics have defined the style as common features appeared in a class of objects. Abstract common features from a set of objects have been used as a bench mark for date and location of original works. Commonalities in shapes are identified by relationships as well as physical properties from shape descriptions. This paper will focus on how the computer and human can recognize common shape properties from a class of shape objects to learn design knowledge. Shape representation using schema theory has been explored and possible inductive generalization from shape descriptions has been investigated. Also learned shape knowledge can be used. for new design process as design concept. Several design process such as parametric design, replacement design, analogy design etc. are used for these design processes. Works of Mario Botta and Louis Kahn are analyzed for explicitly clarifying the process from conceptual ideas to final designs. In this paper, theories of computer science, artificial intelligence, cognitive science and linguistics are employed as important bases.

Influence of particle packing on fracture properties of concrete

  • He, Huan;Stroeven, Piet;Stroeven, Martijn;Sluys, Lambertus Johannes
    • Computers and Concrete
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    • v.8 no.6
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    • pp.677-692
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    • 2011
  • Particle packing on meso-level has a significant influence on workability of fresh concrete and also on the mechanical and durability properties of the matured material. It was demonstrated earlier that shape exerts but a marginal influence on the elastic properties of concrete provided being packed to the same density, which is not necessarily the case with different types of aggregate. Hence, elastic properties of concrete can be treated as approximately structure-insensitive parameters. However, fracture behaviour can be expected structure-sensitive. This is supported by the present study based on discrete element method (DEM) simulated three-phase concrete, namely aggregate, matrix and interfacial transition zones (ITZs). Fracture properties are assessed with the aid of a finite element method (FEM) based on the damage materials model. Effects on tensile strength due to grain shape and packing density are investigated. Shape differences are shown to have only modest influence. Significant effects are exerted by packing density and physical-mechanical properties of the phases, whereby the ITZ takes up a major position.

Solution-Phase Synthesis of Shape-Controlled Metal Nanocrystals

  • Im, Byeong-Gwon
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2011.05a
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    • pp.21.1-21.1
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    • 2011
  • Controlling the morphology of a metal nanocrystal is critical to modern materials chemistry because its physical and chemical properties can be easily and widely tuned by tailoring the size and shape. Combined with ease of synthesis and processing, metal nanocrystals with desired morphologies and thus properties are promising candidates for a wide variety of applications in catalysis, sensing, imaging, electronics, and photonics, and medicine. In this talk, I would like to introduce my recent research results on the shape-controlled synthesis of metal nanocrystals using a simple aqueous method. This water-based system provides a number of merits such as simplicity, convenience, and the potential for large-scale production and enables us to synthesize metal nanocrystals with a rich variety of shapes such as truncated octahedron, cubes, bars, octahedrons, and thin plates. The ability to control the shape of metal nanocrystals provides a great opportunity to systematically investigate their catalytic and optical properties.

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An Investigation for Improvement of Grain Shape and Very Fine Sand of Crushed Sand (부순모래의 입형 및 미립분 함유량 개선을 위한 기술 검토)

  • Kim, Ki-Hoon;Yoon, Seob;Lee, Yong-Sung;Yoon, Gi-Won;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2004.05a
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    • pp.71-74
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    • 2004
  • Recently, with the wide shortage of natural sand resources, it has been increasingly used the crushed sand. rushed sand is made by the process of crushing the rocks artificially, which has different particle properties compared with that of natural sand. Because such different panicle properties of crushed sand results in an undesirable effects of concrete. improvement technology for crushed sand particle properties like grain shape and fine particle needed during the manufacturing process. In this paper, improvement technology of grain shape and fine particle is reported. According to test results, adequate investment for manufacturing facilities like impact crusher and abrasion test machine is required to meet the advanced grain shape and grading of crushed sand. Based on the investigation of test result, mixing of natural land and crushed sand with given proportion can achieve the improvement of grain shape. For improving excessive fine panicle contents. current manufacturing system also can enhance the existing technology for fine particle without additional investment. It can be concluded that adequate investment and research can improve the quality of crushed sand.

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A study on the process technology for controlling the shape and physical properties of melt-blown non-woven (멜트블로운 부직포의 형태와 물리적 특성을 제어하는 공정기술에 관한 연구)

  • Jae-Seok Jeong;Mikyung Kim;Jung Woo Ko
    • Journal of the Korean institute of surface engineering
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    • v.56 no.5
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    • pp.309-319
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    • 2023
  • Non-woven fabric is a textile product made by spinning thermoplastic polymers without manufacturing processes such as stretching, doubling, twisting, weaving, and knitting to form a sheet-shaped web in which fibers are tangled with each other, and then combining them by mechanical and physical methods. In addition, the non-woven fabric manufacturing process has various raw material choices, high productivity, so it is a textile manufacturing technology that can have various uses and increase added value. This study was conducted to control the shape and physical properties of products by improving the manufacturing method of melt-blown non-woven fabrics using process technology that easily changes the shape of non-woven fabrics and improves mechanical properties. In particular, it is considered that a non-woven fabric with a thin material shape and improved mechanical properties will be easily applied to a continuous secondary battery manufacturing industry such as roll to roll operation.

Development and Application of Porous Superelastic TiNi Materials for Medical Implants

  • Gjunter, V.E.
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 1998.10b
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    • pp.7-7
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    • 1998
  • Research activities of Russian Medical Engineering Center and Institute of Medical Materials of Shape Memory Alloys and Implants are presented as follows: ${\bullet}$ The direction of elaboration of porous shape memory alloys for medicine. ${\bullet}$ Medical and technical requirements and physical and mechanical criteria of porous shape memory implants elaboration. ${\bullet}$ Basic laws of heat-, stress- and strain-induced changes of mechanical properties, shape memory effect and superelasticity in porous TiNi-based alloys. ${\bullet}$ Methods of regulation of shape memory effect parameters in porous alloys and methods for controlling the regulation-induced changes of physical and mechanical properties. ${\bullet}$ Original technologies of elaboration of porous alloys In various fields of medicine. ${\bullet}$ Arrangement of serial production of shape memory porous implants and examples of their medical use.

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Thermomechanical and electrical resistance characteristics of superfine NiTi shape memory alloy wires

  • Qian, Hui;Yang, Boheng;Ren, Yonglin;Wang, Rende
    • Smart Structures and Systems
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    • v.30 no.2
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    • pp.183-193
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    • 2022
  • Structural health monitoring and structural vibration control are multidisciplinary and frontier research directions of civil engineering. As intelligent materials that integrate sensing and actuation capabilities, shape memory alloys (SMAs) exhibit multiple excellent characteristics, such as shape memory effect, superelasticity, corrosion resistance, fatigue resistance, and high energy density. Moreover, SMAs possess excellent resistance sensing properties and large deformation ability. Superfine NiTi SMA wires have potential applications in structural health monitoring and micro-drive system. In this study, the mechanical properties and electrical resistance sensing characteristics of superfine NiTi SMA wires were experimentally investigated. The mechanical parameters such as residual strain, hysteretic energy, secant stiffness, and equivalent damping ratio were analyzed at different training strain amplitudes and numbers of loading-unloading cycles. The results demonstrate that the detwinning process shortened with increasing training amplitude, while austenitic mechanical properties were not affected. In addition, superfine SMA wires showed good strain-resistance linear correlation, and the loading rate had little effect on their mechanical properties and electrical resistance sensing characteristics. This study aims to provide an experimental basis for the application of superfine SMA wires in engineering.

Fatigue Properties of Ti-Ni Shape Memory Alloy Wire Welded by Nd: YAG Laser

  • Kim, Y.S.;Kim, J.D.;Kil, B.L.
    • International Journal of Korean Welding Society
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    • v.3 no.1
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    • pp.39-44
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    • 2003
  • The welded specimens were made by butt welding of the 2 wires of 50mm length using the pulsed YAG laser. The laser welded wires were tested for investigating the shape memory effect and the ability of super elasticity. The fatigue properties of the welded wires were investigated using the rotary bending fatigue tester specially designed for wires. Moreover, the effect of defocusing distance during laser welding on the static and fatigue properties was Investigated. The shape memory effect and super elasticity of the laser welded wires were approximately identical with that of base metal at the test temperature below 353K. However, the welded wires were broken within elastic limit at the test temperature above 353k. Under the cyclic bending loading conditions, the welded wires could be useful only below the elastic limit, while the base metal had sufficient fatigue life even the stress induced M-phase region. The fatigue strength of the welded wires was about half of that of the base metal. The deterioration of the static and fatigue properties in the welded wires was proven to be from the large difference of the transformation behavior between the base metal and welded part that is caused by vaporization of Ni-content at the welded part during the welding process. The defocusing distance below 3mm acted more largely on lowering the strength of the welded wires than that of 6mm or 8mm.

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Effect of Composition in Cu-Al-Mn Shape Memory Alloys on the Shape Memory Properties and Cold Workability (Cu-Al-Mn계 형상기억합금에서 조성이 형상기억특성 및 냉간가공성에 미치는 영향)

  • Park, Jong Bae;Park, Hyun Gyoon
    • Journal of the Korean Society for Heat Treatment
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    • v.27 no.2
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    • pp.59-64
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    • 2014
  • Cu-Al-Mn shape memory alloys of a variety of composition were characterized in terms of shape memory properties and cold workability. Cold workability tested by cold rolling indicated that the alloys solution treated in the ${\alpha}+{\beta}$ region have a higher ductility than those solution treated in the ${\beta}$ region. Also it is known that cold workability increased with the decrease in Al content in the ${\beta}$ region. This seems to be resulted from the fact that Mn addition causes to expand ${\beta}$ region toward lower Al content and lower order-disorder transition temperature, consequently, ${\beta}$ of excellent workability being frozen even at room temperature. Experimental results regarding shape memory showed that the properties were better with a higher Al contents at a given Mn content, which is closely related with martensitic transformation. It is also shown that super elasticity limit was enhanced with decrease in the yield strength of alloys because a lower yield strength seems to initiates slip at the lower applied stress.

Recognition of Shape Similarity using Shape Pattern Representation for Design Computation (컴퓨터를 이용한 디자인 프로세스에 있어서 형태패턴의 스키마적 표현을 이용한 건축형태의 유사성 판단에 관한 연구)

  • 차명열
    • Archives of design research
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    • v.15 no.4
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    • pp.337-346
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    • 2002
  • Among many design processes such as learning, storing, retrieving and applying, the process that learns design knowledge is very important for producing creative results that solve design purposes in design computations. The computer should have the ability similar to human in learning design knowledge. It should recognize not only physical properties but also high level design knowledge constructed from the first level physical properties. The high level design knowledge are recognised in terms of isometric translation relationships. This paper explains properties of isometric translation and methods how the computer can recognize high level shape design knowledge using shape pattern representation.

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