• 한국정밀공학회지
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• 제21권12호
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• pp.127-132
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• 2004

It is very important to find out causes of strip pinching for the high quality of products and fer the stable operation of rolling system. We have examined the strip pinching from three points of view to find out the causes of strip pinching in rolling system: strip shape, rolling operation conditions, and behavior of strip. Wedge, off center, and difference of rolling force through CMD(Cross machine direction) are found to possibly provide major initial causes of strip pinching. Generally strip pinching occurred in the tail of strip. Thus, computer simulations by using a FEM code were also carried out to find out the initial mechanism of strip pinching depending upon the force and geometric boundary conditions at the time of strip tail rolling. The strong compression force effect due to the sudden release of strip tail from the work roll and non-uniform strip tail shape (ex. Fish tail) across the CMD were found to provide possible major causes of strip pinching.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1091-1096
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• 2003

It is very important to find out causes of strip pinching for the high quality of products and for the stable operation of hot roiling system. We have examined the strip pinching from three points of view to find out the causes of strip pinching in hot rolling system: strip shape, rolling operation conditions, and behavior of strip. Wedge, off center, and difference of rolling force through CMD are found to possibly provide major initial causes of strip pinching. Generally strip pinching occurred in the tail of strip. Thus, computer simulations by using a FEM code were also carried out to find out the initial mechanism of strip pinching depending upon the force and geometric boundary conditions at the time of strip tail rolling. The strong compression force effect due to the sudden release of strip tail from the work roll and non-uniform strip tail shape (ex. Tongue tail) across the CMD were found to provide possible major causes of strip pinching.

• 생물환경조절학회지
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• 제19권1호
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• pp.31-35
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• 2010

본 실험에서는 국화의 재배방법에 따라 즉, 적심재배방법과 정식시기에 따른 국화 '진바'의 생육과 절화의 상품성과 재배기간의 차이에 미치는 영향에 대하여 알아보고자 하였다. 실험 결과 무적심 재배의 경우 화아 분화 돌입에 필요한 충분한 영양생장기간을 확보하는데 비해, 적심재배의 경우는 충분한 영양 생장기간을 확보하지 못하였다. 화아분화 유기 12주 후의 무적심 재배 개화율은 95%를 상회하였으나 적심재배는 95% 이하로 나타났다. 무적심재배구는 정식시기에 관계없이 3등급상품 이상의 절화가 100% 생산되었으나 적심재배는 첫째주 정식구에서 84.7%로 아주 낮았고 둘째주 정식구는 64.3%, 셋째주 정식구는 18.8%, 넷째주 정식구는 2.6%로 적심재배구의 절화 상품성이 아주 좋지 못하였다. 무적심재배구의 절화품질이 제일 좋지 못한 넷째주 정식구와 적심재배구의 절화품질이 제일 좋은 첫째주 정식구를 비교하면 절화의 품질은 무적심재 배 넷째주 정식구가 좋았고 재배기간도 38일을 단축시킬 수 있었다. 이와 같은 절화국화 무적심재배는 적심 재배에 비하여 재배기간 단축과 품질향상이 가능하므로 경영비 절감과 소득향상이 가능한 재배법으로 판단되었다.

• Earthquakes and Structures
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• 제6권1호
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• pp.89-110
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• 2014

Nonlinear dynamic analyses are carried out to investigate the influence of the pinching hysteretic response of the exterior RC beam-column joints on the seismic behavior of multistory RC frame structures. The effect of the pinching on the local and global mechanisms of an 8-storey bare frame and an 8-storey pilotis type frame structure is evaluated. Further, an experimental data bank extracted from literature is used to acquire experimental experience of the range of the real levels that have to be considered for the pinching effect on the hysteretic response of the joints. Thus, three different cases for the hysteretic response of the joints are considered: (a) joints with strength and stiffness degradation characteristics but without pinching effect, (b) joints with strength degradation, stiffness degradation and low pinching effect and (c) joints with strength degradation, stiffness degradation and high pinching effect. For the simulation of the beam-column joints a special-purpose rotational spring element that incorporates the examined hysteretic options developed by the authors and implemented in a well-known nonlinear dynamic analysis program is employed for the analysis of the structural systems. The results of this study indicate that the effect of pinching on the local and global responses of the examined cases is not really significant at early stages of the seismic loading and especially in the cases when strength degradation in the core of exterior joint has occurred. Nevertheless in the cases when strength degradation does not occur in the joints the pinching may increase the demands for ductility and become critical for the columns at the base floor of the frame structures. Finally, as it was expected the ability for energy absorption was reduced due to pinching effect.

• 화훼연구
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• 제17권2호
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• pp.88-92
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• 2009

본 연구는 붉은꽃인동덩굴의 적심높이(60, 120, 180 cm)가 가지길이, 측지수 및 피복에 미치는 적심높이별 영향을 알아 보기 위하여 수행하였다. 인동덩굴의 줄기길이는 고절위(180 cm) 적심이 저절위(60 cm) 적심보다 길었고, 측지수는 저절위 적심이 고절위 적심보다 많았다. 그러나 분지수는 적심처리간에 큰 차이가 없었다. 퍼골라 벽면의 피복도는 저절위 적심이 85%, 중절위 적심이 74%, 고절위 적심이 62%를 보였다. 개화는 5월 중순부터 10월 중순까지 계속되었고, 첫 개화는 60 cm 적심이 5월 중순으로 가장 빨랐다. 대체로 적심 높이가 낮고 적심시기가 빠를수록 개화가 빨랐고, 개화최성기는 8월 중순이었다. 붉은꽃인동덩굴을 이용한 퍼골라 벽면의 가로 3.0 m ${\times}$ 높이 2.2 m 녹화를 하기 위해서는 퍼골라당 6주(1m당 2주)를 재식하고, 60 cm 벽면 높이에서 1회 적심하면 당년에 85%의 벽면스크린 및 녹화가 가능하였다.

• 한국작물학회지
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• 제49권6호
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• pp.457-462
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• 2004

콩 재배에서 가장 큰 문제의 하나인 도복의 경감을 위한 재배법 개선 방안과 초관 높이 차이에 의한 광합성능력의 향상을 모색하고자 열간 교호 적심이 콩의 생육과 수량에 미치는 영향을 분석한 결과는 다음과 같다. 1. 초관 높이 차이는 무적심 1열+적심 1열에서 가장 컸으며, 도복은 무적심 1열+적심 1열에서 도복경감 효과가 가장 컸다. 2. 제 9본엽의 광합성능력은 무적심 1열+적심 1열의 무적심 열이 가장 높았다. 3. 엽면적지수는 8월 17일 이후에 무적심 열에 비하여 적심 열이 높았고, 9월 5일에는 무적심 1열+적심 1열의 엽면적지수가 가장 높았다. 4. 수량은 무적심 1열+적심 1열에서 주경 상반부의 입수증가와 입중 증대로 전체 무적심에 비하여 $14\%$, 전체 적심에 비하여 $2\%$ 증수되었다.

• 한국자원식물학회지
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• 제24권2호
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• pp.189-194
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• 2011

본 연구는 적심이 감초의 생육 및 수량에 미치는 영향을 구명코자 2008년부터 2009년까지 2년간 충북농업기술원에서 수행하였다. 적심 처리시기에 따라 6월 30일(JUN), 7월 30일(JUL), 8월 30일(AUG), 무적심(대조구) 등 4처리를 하였으며, 적심량은 줄기 길이의 20%를 제거하였다. 본 연구의 결과는 다음과 같이 요약할 수 있다. (1) 초장과 분지수는 적심처리구보다 대조구에서 우수하였으며, 경엽중은 적심시기가 빠를수록 무거웠다. (2) 초장과 줄기 직경은 적심 시기에 따른 영향을 받지 않았다. (3) 지표면의 포복경 생장에는 일정한 경향이 없었다. (4) 본 실험에서 적심이 뿌리 생장을 유도하고, 조기 적심이 뿌리 생육을 촉진하였다. (5) 근중은 대조구 2년생 238 kg/10a에 비해 JUN 처리구와 JUL 처리구에서 각각 11~30% 증가하였으며, 3년생은 대조구 432 kg/10a에 비해 6~11% 증가하였다.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2003년도 ISIS 2003
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• pp.24-27
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• 2003

This paper discusses practical strategies for transition from a pinching to a power grasping, where a multi-fingered hand mounted on a robotic arm envelops a cylindrical object on a table. When the manipulation system grasps a cylindrical object like a pen on a desk, a complete enveloping is not impossible in the initial configuration. The system firstly pinches the object only with two or three fingers and then grasp it with fingers and a palm after regrasping. In this pinching-grasping transition maneuver, human unconsciously selects proper strategy according to some conditions including object dimensions and initial pinching positions. In this paper we therefore develop six possible strategies for this pinching-grasping transition and then investigate their performances for some objects with various dimensions and various grasping positions, using numerical simulations. Based on their results, effective strategies are implemented by using a hand-arm system.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
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• pp.482-485
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• 2006

The response of a reinforced concrete element under cyclic shear is characterized by the hysteretic loops of the shear stress-strain curves. These hysteretic loops can exhibit strength deterioration, stiffness degradation, and a pinched shape. Recent tests have shown that the orientation of steel grids in RC shear elements has a strong effect on the "pinching effect" in the post-yield hysteretic loops. When the steel grid was set at a 45 degree angle to the shear plane, there was no pinching effect and no strength deterioration. However, when the steel grid was set parallel to the shear plane, there was a severe pinching effect and severe strength deterioration with increasing shear strain magnitude. In this paper, two RC elements subjected to revered cyclic shear stresses are considered to study the effect of the steel grid orientation. The presence and absence of the pinching mechanism in the post-yield shear hysteretic loops is studied using the Rotating Angle Softened Truss Model (RA-STM) theory.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2003년도 춘계 학술발표회논문집
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• pp.275-285
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• 2003

Pinching is an important property of reinforced concrete member which characterizes its cyclic behavior. In the present study, numerical studies were performed to investigate the characteristics and mechanisms of pinching behavior and the energy dissipation capacity of flexure-dominated reinforced concrete members. By analyzing existing experimental studies and numerical results, it was found that energy dissipation capacity of a member is directly related to energy dissipated by re-bars rather than concrete that is a brittle material, and that it is not related to magnitude of axial compressive force applied to the member. Therefore, for a member with specific arrangement and amount of re-bars, the energy dissipation capacity remains uniform regardless of the flexural strength that is changed by the magnitude of axial force applied. Due to the uniformness of energy dissipation capacity pinching appears in axial compression member. The flexural pinching that is not related to shear force becomes conspicuous as the flexural strength increases relatively to the uniform energy dissipation capacity. Based on the findings, a practical method for estimating energy dissipation capacity and damping modification factor was developed and verified with existing experiments.