• Title/Summary/Keyword: single curvature

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Robotic harvest of a latissimus dorsi flap using a single-port surgical robotic system in breast reconstruction

  • Joo, Oh Young;Song, Seung Yong;Lew, Dae Hyun;Park, Hyung Seok;Lee, Dong Won
    • Archives of Plastic Surgery
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    • v.48 no.6
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    • pp.577-582
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    • 2021
  • Robot-assisted surgery is evolving to incorporate a higher number of minimally invasive techniques. There is a growing interest in robotic breast reconstruction that uses autologous tissue. Since a traditional latissimus dorsi (LD) flap leads to a long donor scar, which can be an unpleasant burden to patients, there have been many attempts to decrease the scar length using minimally invasive approaches. This study presents the case of a patient who underwent a robot-assisted nipple-sparing mastectomy followed by immediate breast reconstruction with an LD flap using a single-port robotic surgery system. With the assistance of a single-port robot, a simple docking process using a short and less visible incision is possible. Compared to multiport surgery systems, single-port robots can reduce the possibility of collision between robotic arms and provide a clear view of the medial border of the LD where the curvature of the back restricts the visual field. We recommend the use of single-port robots as a minimally invasive approach for harvesting LD flaps.

Strengthening of Substrate Glass for LCD by Single ton Exchange Process (Single Ion Exchange Process에 의한 LCD용 기판유리의 강화)

  • 이회관;오영석;이용수;강원호
    • Journal of the Korean Ceramic Society
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    • v.39 no.7
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    • pp.675-679
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    • 2002
  • To produce a strengthened glass, single ion exchange properties such as three-point bend strength and residual stress were investigated in soda-lime-silicate substrate glass for display use. The present work showed that the maximum value of strength was 62.5${\times}$10$\sub$6/ kg/㎡ after, the two-step single ion exchange process at 470$^{\circ}C$ for 1 h and 450$^{\circ}C$ for 24 h. As the result of the fracture analysis after bending test, the residual stress on the fractured surface of the strengthened glass increased the flexibility by means of absorbing the elastic deformation energy in the glass. Also, the effects of absorbing the elastic deformation energy were analysed by curvature change, number of multiple crack branches and brittleness.

Behavior of lightweight aggregate concrete-encased composite columns

  • Al-Shahari, Abbas M.;Hunaiti, Yasser M.;Ghazaleh, Bassam Abu
    • Steel and Composite Structures
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    • v.3 no.2
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    • pp.97-110
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    • 2003
  • An experimental study was conducted to investigate the behavior of eccentric lightweight aggregate concrete-encased composite columns. This study aims at verifying the validity of such type of concrete in composite construction and checking the adequacy of the AISC-LRFD and the British Bridge Code BS 5400 specifications in predicting the column strength. Sixteen full-scale pin ended columns subjected to uniaxial bending about the major axis in symmetrical single curvature were tested.

Image matching by Wavelet Local Extrema (웨이브릿 국부 최대-최소값을 이용한 영상 정합)

  • 박철진;김주영;고광식
    • Proceedings of the IEEK Conference
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    • 1999.11a
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    • pp.589-592
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    • 1999
  • Matching is a key problem in computer vision, image analysis and pattern recognition. In this paper a multiscale image matching algorithm by wavelet local extrema is proposed. This algorithm is based on the multiscale wavelet transform of the curvature which can utilize both the information of local extrema positions and magnitudes of transform results. This method has advantages in computational cost to a single scale image matching. It is also rotation-, translation-, and scale-independent image matching method. This matching can be used for the recognition of occluded objects.

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Effects of Rotation on the Czochralski Silicon Single Crystal Growth (초크랄스키법에 의한 실리콘 단결정성장에서 회전효과가 미치는 영향에 대한 연구)

  • 김무근
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.19 no.5
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    • pp.1308-1318
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    • 1995
  • The influence of varying rotation speed of both crystal and crucible was numerically investigated for the Czochralski silicon-crystal growth. Based on a simplified model assuming flatness of free surfrae, the Navier-Stokes Boussinesq equations were employed to identify the flow pattern, temperature distribution as well as the shape of the melt/crystal interface. The present results showed that the interface shape was relatively convex with respect to the melt at lower pulling rate and tended to be concave as the pulling rate increased. In particular, the experimentally observed gull-winged shape of the interface was qualitatively in agreement with the predicted shape. The rotation of crystal alone little affected the growth system. When the rotation speed of the crucible was increased, there occurred inversion of the interface shape from convex to concave pattern. At rapid rotation of the crucible, an interesting channel formation was predictied primarily due to the assumption of laminar flow.

Application of curvature of residual operational deflection shape (R-ODS) for multiple-crack detection in structures

  • Asnaashari, Erfan;Sinha, Jyoti K.
    • Structural Monitoring and Maintenance
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    • v.1 no.3
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    • pp.309-322
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    • 2014
  • Detection of fatigue cracks at an early stage of their development is important in structural health monitoring. The breathing of cracks in a structure generates higher harmonic components of the exciting frequency in the frequency spectrum. Previously, the residual operational deflection shape (R-ODS) method was successfully applied to beams with a single crack. The method is based on the ODSs at the exciting frequency and its higher harmonic components which consider both amplitude and phase information of responses to map the deflection pattern of structures. Although the R-ODS method shows the location of a single crack clearly, its identification for the location of multiple cracks in a structure is not always obvious. Therefore, an improvement to the R-ODS method is presented here to make the identification process distinct for the beams with multiple cracks. Numerical and experimental examples are utilised to investigate the effectiveness of the improved method.

Interaction of Magnetic Flux Ropes in Relation to Solar Eruption

  • Yi, Sibaek;Choe, G.S.
    • The Bulletin of The Korean Astronomical Society
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    • v.43 no.2
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    • pp.45.2-45.2
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    • 2018
  • Twisted magnetic flux tubes (also called magnetic flux ropes) are believed to play a crucial role in solar eruptive phenomena. The evolution of a single flux rope with or without the influence of an overlying field of a simple geometry has been extensively studied and its physics is rather well understood. Observations show that interacting flux tubes are often involved in solar eruptions. It was Lau and Finn (1996) who intensively studied the interaction between two flux ropes, whose footpoints are anchored in two parallel planes. In this too simplified setting, the curvature of the flux rope axial fields is totally ignored. In our study, the footpoints of flux ropes are placed in a single plane containing a polarity inversion line as in the real solar active region. Our simulation study is performed for four cases: (1) co-axial field and co-axial current (co-helicity), (2) counter-axial field and co-axial current (counter-helicity), (3) co-axial field and counter-axial current (counter-helicity), and (4) counter-axial field and counter-axial current (co-helicity). Except case 3, each case is found to be related with certain eruptive features.

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Experimental validation of dynamic based damage locating indices in RC structures

  • Fayyadh, Moatasem M.;Razak, Hashim Abdul
    • Structural Engineering and Mechanics
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    • v.84 no.2
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    • pp.181-206
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    • 2022
  • This paper presents experimental modal analysis and static load testing results to validate the accuracy of dynamic parameters-based damage locating indices in RC structures. The study investigates the accuracy of different dynamic-based damage locating indices compared to observed crack patterns from static load tests and how different damage levels and scenarios impact them. The damage locating indices based on mode shape curvature and mode shape fourth derivate in their original forms were found to show anomalies along the beam length and at the supports. The modified forms of these indices show higher sensitivity in locating single and multi-cracks at different damage scenarios. The proposed stiffness reduction index shows good sensitivity in detecting single and multi-cracks. The proposed anomalies elimination procedure helps to remove the anomalies along the beam length. Also, the adoption of the proposed weighting method averaging procedure and normalization procedure help to draw the overall crack pattern based on the adopted set of modes.

Emulsion Properties of Pseudo-Ceramide PC104/Water/Polyoxyethylene Cholesteryl Ether and Polyoxyethylene Cetyl Ether Mixtures.

  • Kim, Do-Hoon;Oh, Seong-Geun;Lee, Young-Jin;Kim, Youn-Joon;Kim, Han-Kon;Kang, Hak-Hee
    • Proceedings of the SCSK Conference
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    • 2003.09b
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    • pp.330-342
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    • 2003
  • The formation of emulsions and micelles in water/ceramide PC104/CholE $O_{20}$/C$_{16}$E $O_{20}$ and water/ceramide PC104/CholE $O_{20}$ mixtures was investigated through the phase behavior studies. The phase diagrams showed the existence of micelle and emulsion regions in both systems. The mixed surfactant system (CholE $O_{20}$/C$_{16}$E $O_{20}$) showed the wider micellar and emulsion regions than the single surfactant system (CholE $O_{20}$). From FT-IR measurements, it was found that the polyoxyethylene (POE) groups of surfactants formed the hydrogen bonds with amido carbonyl group in ceramide PC104. This result indicated that the hydrophilic part (EO) of surfactants could stabilize the lamellar structure and emulsion of ceramide PC104. The mixed surfactant system (CholE $O_{20}$/C$_{16}$E $O_{20}$) resulted in the smaller emulsion droplet size due to the effect of curvature at the interface, thus further increasing emulsion stability. With the penetration of $C_{16}$E $O_{20}$into the interfacial layer of surfactants in emulsion, the curvature of the interface might be altered for the formation of smaller emulsion droplets. The mixed surfactant system could incorporate up to 4 wt. % of ceramide PC104 into emulsion more than single surfactant system.ystem.m.

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Study on dynamic interaction between crack and inclusion or void by using XFEM

  • Jiang, Shouyan;Du, Chengbin
    • Structural Engineering and Mechanics
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    • v.63 no.3
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    • pp.329-345
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    • 2017
  • This paper devoted to study dynamic interaction between crack and inclusion or void by developing the eXtended Finite Element Methods (XFEM). A novel XFEM approximation is presented for these structures containing multi discontinuities (void, inclusion, and crack). The level set methods are used so that elements that include a crack segment, the boundary of a void, or the boundary of an inclusion are not required to conform to discontinuous edges. The investigation covers the effects of a single circular or elliptical void / stiff inclusion, and multi stiff inclusions on the crack propagation path under dynamic loads. Both the void and the inclusion have a significant effect on the dynamic crack propagation path. The crack initially curves towards into the void, then, the crack moves round the void and propagates away the void. If a large void lies in front of crack tip, the crack may propagate into the void. If an enough small void lies in front of crack tip, the void may have a slight or no influence on the crack propagation path. For a stiff inclusion, the crack initially propagates away the inclusion, then, after the crack moves round the inclusion, it starts to propagate along its original path. As ${\delta}$ (the ratio of the elastic modulus of the inclusion to that of the matrix) increases, a larger curvature of the crack path deflection can be observed. However, as ${\delta}$ increases from 2 to 10, the curvature has an evident increase. By comparison, the curvature has a slight increase, as ${\delta}$ increases from 10 to 1000.