• Title/Summary/Keyword: Stillness

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Fuzzy stiffness control of Robot manipulator (로봇 매니퓰레이터의 퍼지 강성 제어)

  • Kang, S.T.;Ji, J.H.;Hong, S.K.
    • Proceedings of the KIEE Conference
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    • 1998.07g
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    • pp.2354-2356
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    • 1998
  • We present a fuzzy model for a robot manipulator and use the model to decide the PD gains of a stiffness controller. Force control applications are extremely difficult to accomplish with such a stiffness robot because robot itself, unknown environment. So we identify a fuzzy model by using Hough transform. We present a method of design of the PD gains of the stiffness controller. We aim at controlling the end-effecor force in the face of uncertainty on the surface stillness. simulation results verify the effectiveness of the proposed strategy.

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New Evaluation and Test of Sidewall's Rotational Stiffness of Radial Tire

  • Kim Young-Woo;Kim Yong-Sung
    • Journal of Mechanical Science and Technology
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    • v.20 no.6
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    • pp.748-758
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    • 2006
  • In this paper, we have revisited the estimation of the rotational stiffness of sidewall of radial tire and have suggested a new method for evaluation of the rotational stiffness. Since thicknesses, and volume fractions of the constituents of sidewall are varied depending on radial position, the equivalent shear modulus of the sidewall also depends on radial position. For the estimation of rotational stiffness of sidewall's rubber, we have divided its cross-section into sufficient numbers of small parts and have calculated the equivalent shear modulus of each part of sidewall. Using the shear moduli of divided parts, we have obtained the rotational stiffness by employing in-plane shear deformation theory. This method is expected to be a useful tool in tire design since it relates such basic variables to the global stillness of tire. Applying the calculation method to a radial tire of P205/60R15, we have compared its rotational stiffness with experimental one.

An Experimental Study on Behavior Characteristic of the Soil Nailed Wall with Facing Stillness (전면벽체 강성에 따른 쏘일네일링 벽체의 거동특성에 관한 실험적 고찰)

  • 김홍택;강인규;권영호;조용훈
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.03a
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    • pp.279-286
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    • 2002
  • Recently, there are many attempts to expand a temporary soil nailing system into a permanent wall due to the advantage of soil nailing system, that is efficient and economic use of underground space and decreasing the total construction cost. However, the proper design approach of a permanent soil nailing system has not been proposed by now in Korea. Permanent soil nailing system which utilizes precast concrete walls for the facing of soil nailing system Is already used in many countries. In general, the cast-in-place concrete facings or rigid walls were constructed in bottom-up way after construction of soil nailing walls finished preliminarily In this paper, various laboratory model tests have been carried out to investigate the failure mode, behavior characteristics, and tensile force at nail head in each load level in respects of the variation of stiffness of the facing.

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A Structural Eigenderivative Analysis by Modification of Design Parameter (설계파라미터 변경에 따른 구조물의 동특성 변화 해석)

  • Lee, Jeong-Yun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.4
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    • pp.739-744
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    • 2002
  • This study predicts the modified structural eigenvectors and eigenvalues due to the change in the mass and stiffness of a structure by iterative calculation of the sensitivity coefficient using the original dynamic characteristics. The method is applied to examples of a cantilever and 3 degree of freedom lumped mass model by modifing the mass and stillness. The predicted dynamic characteristics are in good agreement with these from the structural reanalysis using the modified mass and stiffness.

Postfilic Metamorphorsis and Renaimation: On the Technical and Aesthetic Genealogies of 'Pervasive Animation' (포스트필름 변신과 리애니메이션: '편재하는 애니메이션'의 기법적, 미학적 계보들)

  • Kim, Ji-Hoon
    • Cartoon and Animation Studies
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    • s.37
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    • pp.509-537
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    • 2014
  • This paper proposes 'postfilimc metamorphosis' and 'reanimation' as two concepts that aim at giving account to the aesthtetic tendencies and genealogies of what Suzanne Buchan calls 'pervasive animation', a category that refers to the unprecedented expansion of animation's formal, technological and experiential boundaries. Buchan's term calls for an interdisciplinary approach to animation by highlighting a range of phenomena that signal the growing embracement of the images and media that transcend the traditional definition of animation, including the lens-based live-action image as the longstanding counterpart of the animation image, and the increasing uses of computer-generated imagery, and the ubiquity of various animated images dispersed across other media and platforms outside the movie theatre. While Buchan's view suggests the impacts of digital technology as a determining factor for opening this interdisciplinary, hybrid fields of 'pervasive animation', I elaborate upon the two concepts in order to argue that the various forms of metamorphorsis and motion found in these fields have their historical roots. That is, 'postfilmic metamorphosis' means that the transformative image in postfimic media such as video and the computer differs from that in traditional celluloid-based animation materially and technically, which demands a refashioned investigation into the history of the 'image-processing' video art which was categorized as experimental animation but largely marginalized. Likewise, 'reanimation' cne be defined as animating the still images (the photographic and the painterly images) or suspending the originally inscribed movement in the moving image and endowing it with a neewly created movement, and both technical procedues, developed in experimental filmmaking and now enabled by a variety of moving image installations in contemporary art, aim at reconsidering the borders between stillness and movement, and between film and photography. By discussing a group of contemporary moving image artworks (including those by Takeshi Murata, David Claerbout, and Ken Jacobs) that present the aesthetic features of 'postfilmic metamorphosis' and 'reanimation' in relation to their precursors, this paper argues that the aesthetic implications of the works that pertain to 'pervasive animation' lie in their challenging the tradition dichotomies of the graphic/the live-action images and stillness/movement. The two concepts, then, respond to a revisionist approach to reconfigure the history and ontology of other media images outside the traditional boundaries of animation as a way of offering a refasioned understanding of 'pervasive animation'.

A Semiological Study of Kim Soo-Young′s ″A Variation of Love″ (사랑의 변주곡에 대한 기호학적 접근)

  • 한명희
    • Lingua Humanitatis
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    • v.1 no.2
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    • pp.47-63
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    • 2001
  • "A Variation of Love" is a characteristic Kim Soo-Young poem, in that it embodies the poet′s innovative use of language and proceeds speedily, like many of his other poems. Above all, the poem reveals the core of Kim′s poetical spirit, his speculation about love. The poem is difficult to understand because it broadly uses run-on lines and even run-on stanzas, a technique that many readers are unfamiliar with. The semiological approach of this paper will bring new light on the poem by restructuring the relationship between signs, that is, by taking apart the sign system of the original text and reconstructing its sentence structure. If we rearrange the poem from its original six stanzas and fifty-one lines to four stanzas and twenty-three lines, we will discover a close connection between stanzas 1 and 2, and between stanzas 3 and 4. Of the many keywords of the poem, we may establish the dominant word as "love," into which every poetic word converges and from which each word emanates. Another important keyword is "fatigue of the city" in stanza 4. Similarly negative aspects of the city may be found in the line "the same may be said of Bombay, of New York, of Seoul" in stanza 3, as well as in the words "desire" in combination with "the lamplights of Seoul like leftovers in the pig sty" in stanza 1. The persona of the poem tries to overcome the "fatigue of the city" by "love," but the way he realizes love is, somewhat peculiarly, through stillness and silence. The persona aligns "the stones of the peach and the apricot and the dried persimmon" with the his faith in love. He calls the stones "beautiful hardness" presumably because that hardness (the stillness and silence) may blossom into beauty. In the earlier stanzas, the persona′s quest for love results in an awareness that love is omnipresent, but the persona determines "not to shout it out loud." The reason for this determination is found in stanza 4. Those who experience the "fatigue of the city" will be able to realize it by themselves. This seemingly defeatist conclusion by no means suggest pessimism, for the persona holds the conviction that "there will come a day when [one] will rave for love." This conviction rescues the poem from the dismal mood suggested by the "fatigue of the city." At all events, it is important to note that the "fatigue of the city" should not be considered apart from "love." Yet, strangely enough, the poem embodies a severe critique of the city, and further investigation is necessary in order to clarify why this critique appears in the form of "love." But this will be the treated in another paper.

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FEM Analysis of Smart Skin Structure Specimen (스마트 스킨 구조물 시편의 유한요소 해석)

  • 전지훈;황운봉
    • Composites Research
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    • v.16 no.4
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    • pp.59-65
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    • 2003
  • FEM analysis of the smart skin structure, and application of the sandwich structures investigated. The honeycomb manufactures only provide stillness of thickness direction and transverse shear modulus. Although these are dominant mechanical properties. the other mechanical properties are needed in FEM analysis. Hence, this work shows procedures of obtaining those mechanical properties. Honeycomb material was assumed to be ar, isotropic material and properties are estimated by its dominant honeycomb properties. The other honeycomb properties are then obtained by mechanical properties of Nomex. Buckling test and three point bending test were simulated by ABAQUS. Both the shell and solid element models were used. The results were compared with experimental results and analytical approaches. They showed good agreements. This study shows a guideline of FEM analysis of smart skin structure using commercial a FEM package.

Effects of a drawbar and a rotor in dynamic characteristics of a high-speed spindle (드로우바와 로터가 고속주축계의 동적 특성에 미치는 영향)

  • Chung Won-Jee;Lee Choon-Man;Lee Jung-Hwan;Lim Jeong-Suk
    • Journal of the Korean Society for Precision Engineering
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    • v.23 no.3 s.180
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    • pp.139-146
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    • 2006
  • The spindle system with a built-in motor can be used to simplify the structure of machine tools, to improve the machining flexibility of machine tools, and to perform the high speed machining. For more quantitative analysis of a built-in motor's dynamic characteristics, that of tile mass and stillness effects are considered. And the drawbar in the spindle can be in various condition according to supporting stiffness between drawbar and shaft. Therefore, in this paper following items are performed and analyzed : 1. Modal characteristics of the spindle. 2. Analysis of rotor's mass and stiffness effects. 3. Modal characteristics of the spindle including drawbar, rotor and tool. The results show enough stiff supports must be provided between shaft and drawbar to prevent occurring drawbar vibration lower than the natural frequency of 1st bending mode of the spindle, and considering the mass and stiffness of built-in motor's rotor is important thing to derive more accurate results.

Comparison of Effects among Tai-Chi Exercise, Aquatic Exercise, and a Self-help Program for Patients with Knee Osteoarthritis (슬골관절염 환자를 위한 타이치운동, 수중운동과 자조관리프로그램의 효과비교)

  • Lee Hea-Young
    • Journal of Korean Academy of Nursing
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    • v.36 no.3
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    • pp.571-580
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    • 2006
  • Purpose: This study was to compare the effects among Tai-Chi exercise, aquatic Exercise, and a self-help program for knee osteoarthritis patients on symptoms of arthritis, muscle strength, balance, and difficulty of performing activities. Method: There were 50 final subjects50. A non-equivalent pretest-posttest design was used. The collected data was analyzed using SPSS for Window. One-way ANOVA and Scheffe's multiple comparison test were used 8weeks after each program. Result: There were significant differences in joint pain(p=.000), stillness (p=.001), knee extensor peak torque(p=.006), knee flexor(p=.002), and difficult of performing activity (p=.000), but there was no significant difference in balance(p=.648). The Tai-Chi group was significantly different from the self-help group for knee extensor peak torque, knee flexor and stiffness on Scheffe's multiple comparison tests. In addition, the Tai Chi group or aquatic group were significantly different from the self-help group for difficulty of performing activities(p<0.05). Conclusion: There are significant differences in the effects of the nursing intervention among the three groups. The Tai Chi group and aquatic group were significantly different from the self-help group. However, it seems that Tai-chi exercise may be more suitable than aquatic exercise in osteoarthritis exercise programs. Further studies with a longitudinal study are necessary to confirm the longer exercise period.

The Development of Textile Designs by Using Images of Lotus - Focused on Images of Digital Photograph - (연(蓮) 이미지를 활용한 직물디자인 개발 - 디지털 사진 이미지를 중심으로 -)

  • Jung, Jin-Soun
    • Journal of the Korean Society of Costume
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    • v.61 no.9
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    • pp.50-59
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    • 2011
  • Recently the word "digital" is widely used in almost every field and is dominating this generation. Digital has become the most significant characteristic representing the 21st century, and is leading change across wide range of our life-styles in our culture and thoughts. New art is in harmony with digital in the 21st century. Digital photography is simpler, faster and newer than the analog system of the past. From ancient times, the nature has been the subject of art, and many designers have studied the ways to create beauty from nature. In this study, I chose the lotus as the subject material of textile design development. The lotus invokes a sense of stillness, and nestles many fluid elements, including the curved fluid lotus, rhythmic lotus petal, sinuous lotus leaf, radial vein, lotus pip and oval seed. Therefore, I tried to use these elements of lotus for development of textile design. For this purpose, I photographed the lotus with a digital camera as equipment of design development. Then, on computer, I have developed six textile designs through the process of modification and editing by using the adobe illustrator program.