• Title/Summary/Keyword: 힘의 작용점

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Individual 3D facial avatar synthesis using elastic matching of facial mesh and image (얼굴 메쉬와 이미지의 동적 매칭을 이용한 개인 아바타의 3차원 얼굴 합성)

  • 강명진;김창헌
    • Proceedings of the Korean Information Science Society Conference
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    • 1998.10c
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    • pp.600-602
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    • 1998
  • 본 논문은 정면과 측면 얼굴 이미지의 특성을 살린 3차원 개인 아바타 합성에 관한 연구이다. 표준 얼굴 메쉬를 얼굴 이미지의 특징점에 맞추려는 힘을 특징점 이외의 점들까지의 거리에 대한 가우스 분포를 따라 부드럽게 전달시켜 매쉬를 탄성있게 변형하는 힘으로 작용시켜 메쉬를 얼굴 이미지의 윤곽선을 중심으로 매칭시키고, 매칭된 메쉬가 매칭 이전의 메쉬의 기하학적 특성을 유지할 수 있도록 메쉬에 동적 피부 모델을 적용한다. 이렇게 생성한 3차원 메쉬에 이미지를 텍스춰 매핑하여 개인 특성을 살린 3차원 개인 아바타를 생성한다.

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True Capstan Equation for Fibers and Yarns (섬유와 실에 대한 일반적인 Capstan Equation)

  • 정재호;강태진
    • Proceedings of the Korean Fiber Society Conference
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    • 2003.04a
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    • pp.103-106
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    • 2003
  • 원형의 물체에 접해 있는 섬유 또는 실의 장력에 관하여 기존의 capstan equation의 잘못된 점을 보완하는 일반적인 capstan Equation을 유도하였다. 해석은 주로 섬유-물체의 접촉부위에 초점을 맞추었다. 그 결과 유도된 지배방정식은 2차 상미분 방정식의 형태를 갖는다. 지배방정식의 해를 구한 뒤, 접촉영역 전체에 작용하는 힘의 평형조건을 이용하여 입력 장력(incoming tension)과 출력 장력(outgoing tension)간의 관계식을 얻을 수 있었으며 우리는 이것을 True capstan equation이라 명하였다. (중략)

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A Study on the Static Rigidity of the End Mill (엔드밀의 정적 강성에 관한 연구)

  • 이상규;고성림
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1996.11a
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    • pp.9-14
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    • 1996
  • The deflection of an end mill is very important in machining process and cutting simulation because it affects directly workpiece accuracy, cutting force, and chattering. In this study, the deflection of the end mill was studied both experimentally and by using finite element analysis. And the moment of inertia of radial cross sections of tile helical end mill is calculated for the determination of the relation between cross section and rigidity of tile tools. Using tile Bernoulli-Euler beam and and the concept of equivalent diameter, a deflection model is established, which includes most influence from tool geomety parameters. It was found that helix angle attenuates the rigidity of the end mill.

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THREE DIMENTIONAL FORCE ANALYSIS OF FORCE SYSTEM IN CONTINUOUS ARCHWIRE BY FINITE ELEMENT METHOD (CONTINUOUS ARCHWIRE의 FORCE SYSTEM에 대한 3차원 유한 요소법적 연구)

  • Row, Joon;Ryu, Young-Kyu
    • The korean journal of orthodontics
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    • v.26 no.1 s.54
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    • pp.17-32
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    • 1996
  • It is important to understand the operating mechanism and force system of fixed appliance that most effective for individual tooth movement in various orthodontic appliances. The archwire system of fixed appliance is devided into 3 types, which is continuous arch, segmented arch and sectional arch. The last two types have longer interbracket distance and simple force operating points, so it is easy to control force system by operator. But the continuous arch has shorter interbracket distance and various bracket geometry, so it is hard to control and anaylze the force system. The purpose of this study was three dimentional force and moment analysis of continuous arch system by finite element method, which is similar situation to three dimentional elastic beam in structural engineering. Several sample form of various bracket geometry and artificial lower crowding typodont made by author were constructed, analyzed and compared each other. The results were as follows : 1. The force magnitude is linear proportional to the degree of displacement or tilting of the bracket. 2. The force magnitude is inversely non-linear proportional to the interbracket distance. 3. In three dimensional typodont model, while the force can be compared with that of the sample form in the area where adjacent bracket geometry is simple, the force is much more than the expected value in the area where adjacent bracket geometry is complex.

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Effects of Balance and Kinematic Factors on Archery Score during Archery Shooting (양궁 슈팅 시 균형성과 운동학적 요인이 양궁 점수에 미치는 영향)

  • An, Hyung-Seung
    • Journal of the Korea Convergence Society
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    • v.9 no.5
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    • pp.239-246
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    • 2018
  • In this study, we analyzed the balance of the both legs and the kinematic analysis of the upper limb segments and joints during archery shooting and compared the differences according to the scores. 9 K-university elite archery athletes participated. Each archer was asked to shoot 3-shots and 5-ends on a 122 cm target at a distance of 70 m. Seven infrared cameras (Qualisys, sweden) and two force plates (Kistler, Switerland) were used to calculate the upper limb segments and joint movements and the center of pressure (COP). When the archers shot 8 points, range of motion of elbow joint angle on drawing-arm and mediolateral COP range of motion on the left foot were larger than when 9-10 points were shot (p<.05). In order to maintain a high score in the archery game, constant balance is required, and the balance of the left foot supporting the bow during the shooting is an important factor. In addition, minimizing elbow joint movement of the drawing-arm supporting the bow will help stabilized shooting.

Detection and Analysis of Acoustic Emission Signal at the Epicenter on the Circular Glass Plate During Pencil Land Fracture (연필심 파괴시 유리원판의 진앙점에서 음향방출 신호의 검출 및 해석)

  • Lee, Jong-Gyu;Jang, Ji-Won;Park, Jeong-Man
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.26 no.1
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    • pp.1-7
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    • 1990
  • Theoretical evaluations of the vertical displacement at the epicenter on the circular glass plate have been carried out in the case of the unit point loading(1 dyne force strength) with the Heaviside step-function time dependency. Acoustic emission signals generated during pencil lead($\Phi$=0.5mm, HB) fracture on the soda-lime glass($\Phi$=22cm, thickness=2.8cm) were observed by the optical Michelson interferometer with the stabilized circuit, and then the source function of the observed acoustic emission signals was analyzed by the deconvolution method. The source function of acoustic emission during pencil lead fracture had a 'dip' of~0.7$\mu$sec duration time at the front portion and a step function of~0.5$\mu$sec rise time with a force strength of~4.5N.

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A Study on the Factors for Leveling the Playing Field in Trade Negotiations between the Republic of Korea and the United States: -A Political-Economic Approach to Textile Negotiations(1969 through 1972)- (한-미 통상협상에서의 균등화전략 요소에 관한 연구 - 한-미 섬유협상(1969-1972년)에 대한 정치경제학적 접근 -)

  • Kim, Bong-Hyun;Kwak, Ro-Sung
    • International Area Studies Review
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    • v.13 no.2
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    • pp.550-572
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    • 2009
  • This paper investigates the textile negotiations between Korea and the U.S. which Korea, as a weaker party in the bilateral trade negotiation, was recognized as making a good performance by Odell(1985). Using the documents of Korean governments at the time - Ministry of Foreign Affairs and the Ministry of Commerce and Industry - telegrams and reports from various sources the paper picks a leveling factor during the negotiations. In the paper, we used a dynamic concept of power for describing the negotiating power, and showed Korea succeeded in making the negotiation symmetric using the Special Cooperative Relationship(SCR) as one of the most conspicuous leveling factors during the textile negotiations with the U.S. The paper contributes to finding the factors that can be used in the negotiations with power asymmetry as a leveling factor for weaker country. Also, based on the findings from the paper, future negotiators can get insights on which factors be used, and how to use those factors for leveling the negotiations with a stronger counterpart.

Model on the Elastic Deflection of Temple of the Spectacle Frame (안경테 다리의 탄성변형에 관한 모델)

  • Kim, Dae-Soo
    • Journal of Korean Ophthalmic Optics Society
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    • v.12 no.1
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    • pp.41-51
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    • 2007
  • Differential equations and their solutions were formulated to describe the deflection of the tapered, nonuniform thickness and width's temple, clamped at one end while the perpendicular force is acting on the other end which is freely suspended. The model was derived based on laws of continuity at every point inside the elastic medium that the deflection, tangent slope, bending moment, shearing force must be continuous within the medium. The model is found to be in good agreement with measurements on the beta titanium temple with the correlation 0.992 and p=0.999(Chi test). Therefore it is possible to predict the effect of various temple parameters such as elastic modulus, thickness, width on the deflection of the temples being considered.

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Surface Generation in End Milling considering Tool Deflection (엔드밀 가공시 공구변형을 고려한 표면형성 해석)

  • 이상규
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1996.04a
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    • pp.119-124
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    • 1996
  • End milling operation is very important in machining precision components. Deterioration of surface roughness and surface geometry will cause more process for surface finishing. According to the feed rate and the cutting edge geometry, the cusp which is geometrically uncut surface is determined. To reduce the cost for dinishing operation after end milling, the cusp must be remaianed in small size as possible. Due to the cylindrical type of the end mill, tool deflection is one of the main problems in surface generation. The cutting resistance and the rigidity of the end mill will determine the size of tool deflection. One more important factor which deteriorate surface quality comes from the error in manufacturing end mills. Run-out of end mill which is the difference of the radius of each cutting edges will produce the difference of the cusp size in every rotation of end mill. These three major factors to the surface quality will be analized and the result will be compared with experimental ressult.

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