• Title/Summary/Keyword: Twist1

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Finite Type Invariants and Virtual Twist Moves of Virtual Knots

  • Jeong, Myeong-Ju
    • Kyungpook Mathematical Journal
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    • v.46 no.3
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    • pp.449-461
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    • 2006
  • Generalizing twist moves of classical knots, we introduce $t(a_1,{\cdots},a_m)$-moves of virtual knots for an $m$-tuple ($a_1,{\cdots},a_m$) of nonzero integers. In [4], M. Goussarov, M. Polyak and O. Viro introduced finite type invariants of virtual knots and Gauss diagram formulae giving combinatorial presentations of finite type invariants. By using the Gauss diagram formulae for the finite type invariants of degree 2, we give a necessary condition for a virtual long knot K to be transformed to a virtual long knot K' by a finite sequence of $t(a_1,{\cdots},a_m)$-moves for an $m$-tuple ($a_1,{\cdots},a_m$) of nonzero integers with the same sign.

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Pelvic Twist Analysis, PTA (골반 뒤틀림 변위 분석법에 대한 소고)

  • Jo, Jong-Jin;Kim, Sang-Deok
    • The Journal of Korea CHUNA Manual Medicine
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    • v.5 no.1
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    • pp.135-139
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    • 2004
  • Objectives : The objectives of this report is to introduce PTA. Methods : The examination of the leg length inequality gives us a useful tool for diagnosis of body imbalance. especially pelvic distortion. There are four steps in the process of the leg analysis, according to "The Standard Manual of Chuna Society (2nd ed., Seoul:KCA Press. 2001)". In the last step of the analysis, knee-flexing over $90^{\circ}$, we have often experienced a specific sign that the lower legs are attracted toward one side spontaneously. The authors call it 'Lower Leg Lateral Attraction'. This is a very significant sign that gives us which is the major part between pelvis and the upper parts over sacrum. Thus it is definded as "Pelvic Twist Analysis, PTA" by the authors. With PTA, first, you must check the side of short leg and next, check the side of lateral attraction in lower leg over-flexing. If both sides coincide with each other, then the major part you can correct first is pelvic distortion. If not, you must find another part for primary correction, instead of pelvis. Conclusions : PTA becomes a useful complement to the examination of the leg length inequality.

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Force Prediction and Stress Analysis of a Twist Drill from Tool Geometry and Cutting Conditions

  • Kim, Kug-Weon;Ahn, Tae-Kil
    • International Journal of Precision Engineering and Manufacturing
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    • v.6 no.1
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    • pp.65-72
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    • 2005
  • Drilling process is one of the most common, yet complex operations among manufacturing processes. The performance of a drill is largely dependent upon drilling forces, Many researches focused on the effects of drill parameters on drilling forces. In this paper, an effective theoretical model to predict thrust and torque in drilling is presented. Also, with the predicted forces, the stress analysis of the drill tool is performed by the finite element method. The model uses the oblique cutting model for the cutting lips and the orthogonal cutting model for the chisel edge. Thrust and torque are calculated analytically without resorting to any drilling experiment, only by tool geometry, cutting conditions and material properties. The stress analysis is performed by the commercial FEM program ANSYS. The geometric modeling and the mesh generation of a twist drill are performed automatically. From the study, the effects of the variation of the geometric features of the drill and of the cutting conditions of the drilling on the drilling forces and the stress distributions in the tool are calculated analytically, which can be applicable for designing optimal drill geometry and for improving the drilling process.

A Study on Imprinted Fabrics in Daragook -Focused on the Fabrics of the Okjeon Old Tomb- (다라국 고분군의 수착직물에 관한 연구 -옥전고분군을 중심으로-)

  • 박윤미;정복남
    • Journal of the Korean Society of Costume
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    • v.51 no.7
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    • pp.35-47
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    • 2001
  • This is a research about the fabrics attached to the remains of the Okjeon old tomb which was built around the early 5th century to the mid of the 6th century. Most of the remains have one kind of fabric attached to them, but there are cases where different sorts of fabrics are attached, where one kind is attached in layers, and there are also cases where the layer is made of different types of fabrics. Although they are made of warps and wefts with no twists, there can be an S twist on the weft or on both the warp and weft, and only one Z twist can be seen. There are 81 fabrics of plain weaved, one of transformed plain weaved and five 4-end complex gauze in these remains. The sparsest plain weaved fabric has the density of 7.4 strands/cm, while the most dense fabric has the density of 148.2$\times$129.1 strands/cm and 0.046$\times$0.061/mm thickness in thread. All the fabrics observed by SEM are hemp except one silk.

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RESTRICTION OF SCALARS AND CUBIC TWISTS OF ELLIPTIC CURVES

  • Byeon, Dongho;Jeong, Keunyoung;Kim, Nayoung
    • Journal of the Korean Mathematical Society
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    • v.58 no.1
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    • pp.123-132
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    • 2021
  • Let K be a number field and L a finite abelian extension of K. Let E be an elliptic curve defined over K. The restriction of scalars ResKLE decomposes (up to isogeny) into abelian varieties over K $$Res^L_KE{\sim}{\bigoplus_{F{\in}S}}A_F,$$ where S is the set of cyclic extensions of K in L. It is known that if L is a quadratic extension, then AL is the quadratic twist of E. In this paper, we consider the case that K is a number field containing a primitive third root of unity, $L=K({\sqrt[3]{D}})$ is the cyclic cubic extension of K for some D ∈ K×/(K×)3, E = Ea : y2 = x3 + a is an elliptic curve with j-invariant 0 defined over K, and EaD : y2 = x3 + aD2 is the cubic twist of Ea. In this case, we prove AL is isogenous over K to $E_a^D{\times}E_a^{D^2}$ and a property of the Selmer rank of AL, which is a cubic analogue of a theorem of Mazur and Rubin on quadratic twists.

Twist CT 촬영에 대한 고찰

  • Choi, Kwang-Nam;Gong, Seok-Gyo;Sin, Hun-Cheol;Lee, Je-Ho
    • Proceedings of the Korean Society of Radiological Science
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    • 1994.10a
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    • pp.111.1-111.1
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    • 1994
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The Relation Between Magnetic Field Configuration And The Flux Expansion Factor

  • Lee, Hwan-Hee;Magara, Tetsuya;An, Jun-Mo;Kang, Ji-Hye
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.1
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    • pp.85.1-85.1
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    • 2012
  • In this study we use three-dimensional magnetohydrodynamic simulations of flux emergence from solar subsurface layer to corona. In order to study the twist parameter of magnetic field we compare the simulations for strongly twisted and weakly twisted cases. Based on the results, we derive a flux expansion factor of selected flux tubes which is a ratio of expanded cross section to the one measured at the footpoint of the flux tube. To understand the effect of flux expansion factor, we make a comparison between magnetic field configuration and the expansion factor. By using a fitting function of hyperbolic tangent we derive noticeable correlations among the strength of the vertical magnetic field, current density and expansion factor. We discuss what these results tell about the relationship between the twist of emerging field and the mechanism for the solar wind.

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A Study on the Threadline Instability on the Belt-type Texturing Process (벨트형 가연공정에서의 사도불안정에 관한 연구)

  • 이민수;김승진;박경순
    • Textile Coloration and Finishing
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    • v.16 no.1
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    • pp.5-9
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    • 2004
  • This research surveys the threadline instability on the belt texturing machine according to the 1st heater temperature, draw ratio and velocity ratio. the threadline instability to the time, which is called surging phenomena, is analysed with variations of draw ratio and velocity ratio. In addiction, the surging phenomena is investigated with the variation of the untwisting tension and false twist mechanism on the belt texturing machine. The breaking strain, modulus and yam unevenness of the DTY along the yarn length are measured and analysed with the surging phenomena which is due to untwisting tension variation on the threadline according to the draw ratio, 1st heater temperature and velocity ratio.

Increased Hypermethylation of Glutathione S-Transferase P1, DNA-Binding Protein Inhibitor, Death Associated Protein Kinase and Paired Box Protein-5 Genes in Triple-Negative Breast Cancer Saudi Females

  • Hafez, Mohamed M.;Al-Shabanah, Othman A.;Al-Rejaie, Salim S.;Al-Harbi, Naif O.;Hassan, Zeinab K.;Alsheikh, Abdulmalik;Theyab, Abdurrahman I. Al;Aldelemy, Meshan L.;Sayed-Ahmed, Mohamed M.
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.2
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    • pp.541-549
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    • 2015
  • Triple negative breast cancer (TNBC) is an aggressive subtype of breast cancer (BC) with higher metastatic rate and both local and systemic recurrence compared to non-TNBC. The generation of reactive oxygen species (ROS) secondary to oxidative stress is associated with DNA damage, chromosomal degradation and alterations of both hypermethylation and hypomethylation of DNA. This study concerns differential methylation of promoter regions in specific groups of genes in TNBC and non-TNBC Saudi females in an effort to understand whether epigenetic events might be involved in breast carcinogenesis, and whether they might be used as markers for Saudi BCs. Methylation of glutathione S-transferase P1 (GSTP1), T-cadherin (CDH13), Paired box protein 5 (PAX5), death associated protein kinase (DAPK), twist-related protein (TWIST), DNA-binding protein inhibitor (ID4), High In Normal-1 (HIN-1), cyclin-dependent kinase inhibitor 2A (p16), cyclin D2 and retinoic acid receptor-${\beta}$ ($RAR{\beta}1$) genes was analyzed by methylation specific polymerase chain reaction (MSP) in 200 archival formalin-fixed paraffin embedded BC tissues divided into 3 groups; benign breast tissues (20), TNBC (80) and non-TNBC (100). The relationships between methylation status, and clinical and pathological characteristics of patients and tumors were assessed. Higher frequencies of GSTP1, ID4, TWIST, DAPK, PAX5 and HIN-1 hypermethylation were found in TNBC than in non-TNBC. Hypermethylation of GSTP1, CDH13, ID4, DAPK, HIN-1 and PAX5 increased with tumor grade increasing. Other statistically significant correlations were identified with studied genes. Data from this study suggest that increased hypermethylation of GSTP1, ID4, TWIST, DAPK, PAX5 and HIN-1 genes in TNBC than in non-TNBC can act as useful biomarker for BCs in the Saudi population. The higher frequency of specific hypermethylated genes paralleling tumor grade, size and lymph node involvement suggests contributions to breast cancer initiation and progression.