• 한국운동역학회지
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• 제13권3호
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• pp.81-98
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• 2003

The purpose of this study is to closely examine kinematic characteristics by jump phase of Li Xiaopeng motion in horse vaulting and provide the training data. In doing so, as a result of analyzing kinematic variables through 3-dimensional cinematographic using the high-speed video camera to Li Xiaopeng motion first performed at the men's vault competition at the 14th Busan Asian Games, the following conclusion was obtained. 1. It was indicated that at the post-flight, the increase of flight time and height and twisting rotational velocity has a decisive effect on the increase of twist displacement. And Li Xiaopeng motion showed longer flight time and higher flight height than Ropez motion with the same twist displacement of entire movement. Also the rotational displacement of the trunk at peak of COG was much short of $360^{\circ}$(one rotation) but twist displacement showed $606^{\circ}$. Likewise, Li Xiaopeng motion was indicated to concentrate on twist movement in the early flight. 2. It was indicated that at the landing, Li Xiaopeng motion gets the hip to move back, the trunk to stand up and the horizontal velocity of COG to slow down. This is thought to be the performance of sufficient landing, resulting from large security of rotational displacement of airborne and twist displacement. 3. It was indicated that at the board contact, Li Xiaopeng motion made a rapid rotation uprighting the trunk to recover slowing velocity caused by jumping with the horse in the back, and has already twisted the trunk nearly close to $40^{\circ}$ at board contact. Under the premise that elasticity is generated without the change of the feet contacting the board, it will give an aid to the rotation and twist of pre-flight. Thus, in the round-oH phase, the tap of waist according to the fraction and extension of hip joint and arm push is thought to be very important. 4. It was indicated that at the pre-flight, Li Xiaopeng motion showed bigger movement than the techniques of precedented studies rushing to the horse, and overcomes the concern of relatively low power of jump through the rapid rotation of the trunk. Li Xiaopeng motion secured much twist distance, increased rotational distance with the trunk bent forward, resulting in the effect of rushing to the horse. 5. At horse contact, Li Xiaopeng motion makes a short-time contact, and maintains horse take-off angle close to vertical, contributing to the increase of post-flight time and height. This is thought to be resulted from rapid move toward movement direction along with the rotational velocity of trunk rapidly earned prior to horse contact, and little shave of rotation axis according to twist motion because of effective twist in the same direction.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2000년도 제1회 학술대회 논문집
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• pp.193-194
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• 2000

We have calculated the d/p boundary values in which the low twist defect and the stripe domain defect can occur with dielectric constants and elastic constants and compared them with experimental data using the compensation factors. We estimated d/p margin for $250^{\circ}$ twist angle without experimental data and investigated qualitatively the reasonability of the behavior.

• Progress in Superconductivity
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• 제1권2호
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• pp.141-145
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• 2000

Different twist pitches of multi filamentary BSCCO 2223 tapes using high resistivity sheath were fabricated to investigate the effect of twist pitches on the microstructure and critical current property. A conductor with a high resitstivity matrix is possible to allow larger twist pitch for reducing ac losses and reduce eddy current losses simultaneously. The $J_{ct}$ values of 10 mm and 5 mm twisted tapes drop faster than that of untwisted and 20 mm twisted tapes under increasing magneticfield, especially in low field regime (0 $\sim$ 0.03 T). It suggests that weak links in the former are more serious than in the latter, which is in accordance with the microstructure analysis.

• 감성과학
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• 제11권4호
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• pp.449-460
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• 2008

중동지역은 PET 합섬직물이 이들의 평상복으로 많이 사용되고 있으며, 여성복은 차도르(Chador) 그리고 남성복은 토베(Thobe)라고 불려진다. 그리고 이들 PET 직물은 미세한 촉감특성에 따라서 수출가격의 큰 차이를 가져오며 원사의 특성과 제조공정 특성에 의해 미세한 감성촉감의 차이를 유발한다. 본 연구에서는 고가에 팔리고 있는 일본 데이진 제품과 비교하여 본 연구에서 개발된 중동 남성복 Thobe 제품의 감성특성을 분석하고 미세한 감성촉감의 원인을 규명하여 원사 및 최적 생산공정조건에 관한 연구를 수행하였다. 본 연구에서는 일본 데이진 직물 4가지를 목표품질시료로서 준비하였고, 개발을 위한 시생산제품으로 5가지 직물을 시생산하였다. 실의 굵기, 꼬임수 그리고 실의 세팅조건 및 직물의 밀도 등을 바꾸어 연축과 직축 그리고 가공축 등의 설계조건을 바꾸어 주었다. 본 연구수행의 결과 데이진 Thobe 제품의 감성특성을 원사 및 직물에서 분석하고 이들 감성특성 분석 자료를 바탕으로 사가공(絲加工)기술과 3차원 직물설계 시뮬레이션 기술을 바탕으로 감성 토베 직물의 설계기술을 확립하였다.

• 반도체디스플레이기술학회지
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• 제14권2호
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• pp.47-52
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• 2015

In this paper, the performance of uncoated- and Titanium nitride aluminium TiAlN-PVD coated- carbide twist drills were investigated when drilling aluminium alloy, Al 6061. This research focuses on the optimization of drilling parameters using the Taguchi technique to obtain minimum surface roughness and thrust force. A number of drilling experiments were conducted using the L9 orthogonal array on a CNC vertical machining center. The experiments were performed on Al 6061 material l blocks using uncoated and coated HSS twist drills under dry cutting conditions. Analysis of variance(ANOVA) was employed to determine the most significant control factors. The main objective is to find the important factors and combination of factors influence the machining process to achieve low surface roughness and low cutting thrust force. From the analysis of the Taguchi method indicates that among the all-significant parameters, feed rate are more significant influence on surface roughness and cutting thrust than spindle speed.

• Fibers and Polymers
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• 제7권4호
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• pp.398-403
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• 2006

Dimensional constants (k values) of single jersey fabrics made from $LincLITE^{(R)}$ and conventional yams are calculated under dry, steam, full relaxation treatments. Fabrics were made under different tightness factors such as high, medium and low with different twist factors, twist directions and feeder blending. $LincLITE^{(R)}$ yarns made to get soft and bulkier effects with yam count of 39 tex and conventional yams made into 39 tex and 48 tex yam counts. Various effects on K values are analysed using correlation coefficients. K-values are increased with relaxation progression and have shown some differences between in $LincLITE^{(R)}$ and conventional fabrics, and feeder blended fabrics. Loop shape factor is highly affected by tightness factor, relaxation and feeder blending in $LincLITE^{(R)}$ fabrics, whereas twist factor not significantly effects on loop shape factor in conventional fabrics. Stitch density significantly increases with relaxation in conventional fabrics and no significant effect shows with $LincLITE^{(R)}$ fabrics.

• 한국의류산업학회지
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• 제12권4호
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• pp.500-507
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• 2010

In this study, physical properties were studied by using latent stretching yarn in order to develop the texturing yarn technique for super bulky yarn, which is better in bulkiness and handle than natural wool and also adds property of synthetic fiber to natural wool. In order to obtain textured conditions by analysing basic properties for manufacturing DTY yarn with super bulky property, DTY 50d/12 after spinning latent yarn spined POY 80d/12 was obtained under the two conditions of (i) false twist(T/M) level 3 in DTY texturing and (ii) draw ratio level 4 in draw texturing. For DTY texturing yarn, Elongation rate increased as the heat treatment time and temperatures increased. In addition, shrinkage became higher as false twist was higher, so that elongation rate became lower. When annealing became longer in time and higher in temperature, initial modulus increased. In addition, as the count of false twist increased, the initial modulus showed higher values. For draw texturing yarn, under the conditions of heat temperature 180 and heating time 30 minutes, shrinkage rate in draw ratio 1.55 and 1.6 draw ratio was 7%, and that in 1.65 and 1.7 draw ratio was 8.5%. High draw ratio samples' tenacity was much influenced by heating time and temperature, but low draw ratio samples' tenacity was influenced not by treated time, but by treated temperature.

• 한국자원식물학회지
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• 제31권1호
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• pp.71-76
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• 2018

본 연구는 수세가 강한 '캠벨얼리'를 시험재료로 착립률 증진을 위한 개화기 신초 비틀기의 효과를 규명하기 위하여 수행되었다. 수세가 강한 '캠벨얼리'의 신초 비틀기 처리에 따른 발아기 및 개화기는 처리별 차이가 없었으나 수확기는 3일 정도 지연되었다. 신초 비틀기 처리구에서 수확기가 지연된 것은 '캠벨얼리'의 과방중과 착립률이 개화전 7일과 개화시 모두 3절 비틀기 처리구에서 높게 나타났기 때문이었다. 신초 비틀기에 의한 '캠벨얼리'의 가용성 고형물 및 산도는 처리간 차이를 보이지 않았으나, 수량은 '개화 전 7일 3절 비틀기' 처리에서 12.1 kg/주으로 무처리에 비하여 1.6배 증가하였다. 안토시아닌 함량은 무처리에 비하여 수량이 많은 처리구에서 낮았으나 착색도인 Hunter 값은 처리간 유의적 차이를 보이지 않았다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2000년도 제1회 학술대회 논문집
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• pp.195-196
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• 2000

Fast response time is realized by using LTN-LCDs. To calculate the dynamic electro-optical characteristics, Ericksen-Leslie theory is used for the dynamic profile of molecules and order tensor representation is adopted for the free energy calculation.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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• pp.207-210
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• 2007

We fabricated an optically compensated bend cell with pixel-isolating polymer wall. The polymer wall was formed by phase separation of LCs and UVcurable polymer. The fabricated cell had initially ${\pi}-twist$ state. It showed low driving voltage, wide viewing angle and fast response properties. Also, polymer wall provided the mechanical stability preventing distortion of a display image from pressure.