• 대한기계학회논문집A
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• 제28권11호
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• pp.1752-1759
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• 2004

Reinforced braid layer (RBL) in automobile power steering hose plays an important role in power steering system. When the working oil is applied to the power steering hose, RBL suppresses rubber hose deformation from internal pressure and heat expansion. RBL is woven textile composites having a double-row structure of nylon cords twisted with the specific helix angle. In this paper, effective material properties of RBL are estimated using a detailed 3-D finite element model considering its complicated geometry. Numerical experiments based on a superposition method are carried out to simulate uniaxial tensile loading condition.

• Kyungpook Mathematical Journal
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• 제57권2호
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• pp.331-360
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• 2017

Unknotting numbers for torus knots and links are well known. In this paper, we present a new approach to determine the position of unknotting number crossing changes in a toric braid such that the closure of the resultant braid is equivalent to the trivial knot or link. Further we give unknotting numbers of more than 600 knots.

• Korean Journal of Mathematics
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• 제19권4호
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• pp.409-421
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• 2011

We study a natural map from the braid group to the mapping class group which is called Harer map. It is rather new and different from the classical map which was studied in 1980's by F. Cohen, J. Harer et al. We show that this map is homologically trivial for most coefficients by using the fact that this map factors through the symmetric group.

• Kyungpook Mathematical Journal
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• 제55권4호
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• pp.753-771
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• 2015

A complete invariant defined for (closed connected orientable) 3-manifolds is an invariant defined for the 3-manifolds such that any two 3-manifolds with the same invariant are homeomorphic. Further, if the 3-manifold itself can be reconstructed from the data of the complete invariant, then it is called a characteristic invariant defined for the 3-manifolds. In a previous work, a characteristic lattice point invariant defined for the 3-manifolds was constructed by using an embedding of the prime links into the set of lattice points. In this paper, a characteristic rational invariant defined for the 3-manifolds called the characteristic genus defined for the 3-manifolds is constructed by using an embedding of a set of lattice points called the PDelta set into the set of rational numbers. The characteristic genus defined for the 3-manifolds is also compared with the Heegaard genus, the bridge genus and the braid genus defined for the 3-manifolds. By using this characteristic rational invariant defined for the 3-manifolds, a smooth real function with the definition interval (-1, 1) called the characteristic genus function is constructed as a characteristic invariant defined for the 3-manifolds.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1892-1893
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• 2007

Because High efficiency electric vehicles use electrical energy by an power source, radiated noise at high voltage cable bring on problems at other electric/electronic components. But, in order to insure shielding effectiveness increasing braid density infinitely, it is possible that the cost is more than one third of cost of manufacturing cable. Accordingly in this paper, we studied design of cost-effective and light shield cable using dual shielding system of braid and al-foil.

• 대한수학회논문집
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• 제21권2호
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• pp.337-345
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• 2006

John Harer conjectured that the canonical map from braid group to mapping class group induces zero homology homomorphism. To prove the conjecture it suffices to show that this map preserves the first Araki-Kudo-Dyer-Lashof operation. To get information on this homology operation we need to investigate the image of braiding under the Harer map. The main result of this paper is to give both algebraic and geometric interpretations of the image of braiding under the Harer map. For this we need to calculate long chains of consecutive actions of Dehn twists on the fundamental group of surface.

• 한국세라믹학회지
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• 제54권1호
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• pp.23-27
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• 2017

A series of $CeO_2-TiO_2$ composite samples with different Ce/Ti molar ratios were prepared by the paper template. Powder X-ray diffraction (XRD) and transmission electron microscopy (TEM) were used to confirm a face-centered cubic lattice of $CeO_2$ with Ce/Ti =8:2 or 9:1 and a two phase mixture of anatase titania and face-centered cubic ceria with Ce/Ti = 7 : 3. The field emission scanning electron microscopy (FESEM) results suggest that the products are micron braid structures consisting of fibers with diameters in a range of $1-6{\mu}m$ and lengths of several hundred micrometers. $N_2$ absorption-desorption testing shows that the composite at Ce/Ti molar fraction of 8 : 2 has the largest BET surface area (about $81m^2{\cdot}g^{-1}$). Compared to the pure $CeO_2$ sample, the composites show superior catalytic activity for $H_2$ reduction and CO oxidation. For the micron braid structure $CeO_2-TiO_2$ composite (Ce/Ti = 8 : 2), due to the high surface area and the solid solution with appropriate $Ti^{4+}$ incorporation, the CO conversion at about $280^{\circ}C$ was above 50% and at $400^{\circ}C$ was 100%.

• 한국항행학회논문지
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• 제22권2호
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• pp.105-110
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• 2018

오늘날 북핵문제는 한반도와 동북아시아에 심각한 안보 위협 요인으로 대두되고 있다. 이에 따라 우리 군은 휴전선에서 수백 Km 떨어진 상공에서도 평양 등 북한 지휘부 건물과 핵시설을 정밀 타격할 수 있는 장거리 공대지 유도탄의 해외 도입과 국내 개발을 추진하고 있다. 본 논문에서는 장거리 공대지 유도탄 개발을 위한 여러 설계 요소 중 유도탄 경량화를 위한 탄내케이블 브레이드를 제거하고 이에 따른 성능을 예측 및 분석하였다. 브레이드 제거에 따른 탄내케이블 뭉치 내부의 누화 (cross-talk) 및 군사 EMI 규격인 MIL-STD-461F의 내성(conduction susceptibility) CS114 및 방사(radiated emission) RE101 규격을 적용하여 시뮬레이션을 통해 브레이드 제거 가능성을 분석하였다.

• 대한수학회지
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• 제36권2호
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• pp.243-256
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• 1999

We will consider f,g : S1longrightarrowS2 a pair of maps between two orientable compact surfaces. The purpose of this paper is to decide when the pair can be deformed to a pair (f', g') such that

• 대한수학회보
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• 제25권2호
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• pp.247-251
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• 1988

This note gives a combinatorial treatment to the problem finding a generating set among conjugating automorphisms of a free group and to the method deciding when a conjugating endomorphism of a free group is an automorphism. Our group of pseudo-conjugating automorphisms can be thought of as a generalization of the artin's braid group.