• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.11a
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• pp.869-870
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• 2010

• Journal of Biosystems Engineering
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• v.28 no.1
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• pp.19-26
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• 2003

An oscillating digger mechanism was designed, constructed. and tested. The mechanism is consisted of a six-bar linkage, one four-bar linkage was fer the digger blade and the other one fur variable soil-crop separation. Experimental variables were amplitude(3, 6, 9 mm). frequency(11.2, 14.9. 17.0 Hz), and forward speed of tractor(0.91, 1.13, 1.56 km/h). Each combination of these variables was replicated three times to measure the draft and torque for power requirement evaluation. and the broken-up soil height on the soil separation sieve mechanism. Four parameters λ(the ratio of vibration speed to forward velocity), p(the ratio of vibration acceleration to forward velocity), K(the ratio of vibration acceleration to gravitational acceleration), and T(the product of λ and K) were induced from three experimental variables: amplitude, frequency, and tractor speed. And the power requirement and soil separation ability were analyzed by regression. Though λ and K were known to be the representative parameters. T was the most moderate one to explain draft. torque. and soil separation in this study. It was estimated that the T equal to or greater than 2.4 was the minimum recommended value. Figure 18 would be useful fir the selection of amplitude. frequency, or operating tractor speed once any two variables are known.

• Journal of Biosystems Engineering
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• v.8 no.2
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• pp.26-38
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• 1983

Binder harvesters introduced to Korea were originally designed to be used for Japonica varieties which are highly resistant to shattering. In order to improve the performance of the binder to Indica varieties which are easily shattered and have shorter stem, mechanical modifications of the binder are inevitable. Shattering losses of the binder can be classified into two major parts; one incurred before and one after binding operations. The latter has been evaluated as great as the former. Previous studies indicated that the high discharge losses resulted from a great impact force of the discharge arm on the rice bundle during the discharge process. This study was intended to theoretically analyze the discharge mechanism of four-bar linkage. For this purpose, two commercially available binder harvesters having a four-bar linkage as a discharge mechanism were analyzed. Using the results from the motion analysis and the other structural constraints of the machines, they were modified and experimentally compared with the machines without modification to see whether any decrease in grain losses was obtained. The results obtained in this study are summarized as follows: 1. The path, velocity and acceleration of discharge arm were computer analyzed by vector analysis. Using results of the analysis and intrinsic constraints of the binder, discharge mechanism was modified to reduce the impact force on bundle by discharge arm in the range where the discharge performance was not deteriorated. This modification of the discharge mechanism could be done with an aid of four-bar linkage synthesis technique. As a result, average velocity and acceleration of the discharge arm during the discharge process were reduced respectively by 19 percent and 33 percent for binder A, and 17 percent and 35 percent for binder B. 2. Through the modification of the discharge mechanism, discharge losses of binder A were reduced by 42-56 percent for Milyang 23, Poongsan and Hangang chal, and discharge losses of binder B were reduced by 13-20 percent for Milyang 23 and Poongsan. 3. Discharge losses were decreased as the bundle size became larger and the size effect on the decrease rate appeared more significant in the binders with modifications than in those without modifications.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.27-27
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• 2017

The rapid growth of world population, reduction of cultivated areas for crop production, and detrimental effects of pests, diseases, and climate changes have required to breed new rice cultivars with high yield, accepted quality, but strong resistance to abiotic and biotic stresses. However, traditional breeding needs much time to breed a new cultivar, whereas the successful use of molecular breeding is still questionable. We have developed a novel mutation which allow to cross many rice cultivars together with low segregation, that allow to breed a new cultivar in only several cropping. The mechanism has been unknown, but we suggest that gene linkage may play a crucial role, of which the semi dwarf gene might be the center gene for gene linkage occurrence. The phenomenon of this possible gene linkage is contrary to Mendel rules, but it is promising to breed new rice cultivars, of which, the most elite genes in rice might be able to gather in a targeted rice variety.

• International Journal of Precision Engineering and Manufacturing
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• v.5 no.4
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• pp.43-49
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• 2004

A spring-actuated linkage system is used to satisfy the desired opening and closing characteristics of the electric contacts of a vacuum circuit breaker. If the type of a circuit breaker and the structure of the linkage system are predetermined, then design parameters such as stiffness, free length and attachment points of the spring become the important issues. In this paper, based on the energy conservation, the total system energy is constant throughout the operating range of the mechanism; a systematic procedure to optimize the spring design parameters is developed and applied to a simplified mechanism of a circuit breaker. The developed procedure is converted to the environment of the multi-body dynamics program, ADAMS for an in-depth consideration of the complex dynamics of a circuit breaker mechanism.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.5
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• pp.2031-2037
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• 2011

The French doors have the advantage that they can use inner space more efficiently due to without of partition between two rooms. However, when they are used for refrigerators, the door gaskets for sealing may cause interference of themselves during opening and closing, which causes fatal effect on sealing by worn out of the gaskets as well as increases door opening force. This research proposes a new mechanism for the French doors using the parallelogram motion of 4-bar linkage mechanism, which does not make any interference between gaskets. We manufactured the French doors of proposed mechanism to verify that they do not cause any interference during opening and closing, as well as opening force is decreased. The use of our developed mechanism is not limited to refrigerators, but can be extended to other industrial products with the French doors.

• The Journal of Korea Robotics Society
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• v.11 no.4
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• pp.193-204
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• 2016

This paper presents an anthropomorphic finger prosthesis for amputees whose proximal phalanx is mutilated. The finger prosthesis to be proposed is able to make the amputees to perform the natural motion such as flexion/extension as well as self-adaptive grasping motion as if normal human finger does. The mechanism of finger prosthesis with three degrees-of-freedom (DOFs) consists of two five-bar and one four-bar linkages. Two passive components composed of torsional spring and mechanical stopper and only one active joint are employed in order to realize an underactuation. Each passive component is installed into the five-bar linkage. In order to activate the finger prosthesis, it is required for the user to flex and extend the remaining proximal phalanx on the metacarpophalangeal (MCP) joint, not an electric motor. Thus the finger prosthesis conducts not only the natural motion according to his/her intention but also the grasping motion through the deformation of springs by the object for human finger-like behavior. In order to reveal the operation principle of the proposed mechanism, kinematic analysis is performed for the linkage design. Finally both simulations and experiments are conducted in order to reveal the design feasibility of the proposed finger mechanism.

• Proceedings of the KSME Conference
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• 2005.11a
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• pp.181.1-181.1
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• 2005

• Proceeding of EDISON Challenge
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• 2017.03a
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• pp.602-607
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• 2017

본 연구는 4족 보행 로봇을 설계하기 위해 linkage of jansen mechanism을 선택하였고 설정한 보행 목적에 맞는 최적 링크의 길이를 구하기 위해 Edison SW를 사용하여 해석을 하고 수치적 해석을 동원하여 목표에 대한 신뢰를 높인다.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.6
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• pp.108-113
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• 2021

Recently, a new concept of a one-touch descending lifeline has been proposed to address the drawbacks of the conventional descending lifeline, which can be easily installed and quickly evacuated in the case of a fire emergency. All separate parts for escape are initially mounted in a box, and the link-type support is spread out of the window by pushing the handle attached to the box. In this study, the proposed double square linkage mechanism was redesigned, and its safety is verified by determining an appropriate moment of inertia of the link through finite element analysis using Abaqus. The shape and assembling method of the reel and speed controller were also modified such that the safety belt was simultaneously unfolded with link-type support. Finally, the feasibility of the proposed one-touch all-in-one descending lifeline was confirmed through fabrication.