• The Journal of Korea Robotics Society
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• v.17 no.4
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• pp.484-492
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• 2022

This paper presents a simple and robust under-actuated robotic finger mechanism that enables self-adaptive grip, fingertip pinch, and caging grasp functions. In order to perform daily activities using hands, the fingers should be able to perform adaptive gripping and pinching motion, and the caging grasp function is required to realize natural gripping motions and improve grip reliability. However, general commercial prosthetic hands cannot implement all three functions because they use under-actuation mechanism and simple mechanical structure to achieve light-weight and high robustness characteristic. In this paper, new mechanism is proposed that maintains structural simplicity and implements all the three finger functions with simple one degree-of-freedom control through a combination of a four-bar linkage mechanism and a wire-driven mechanism. The basic structure and operating principle of the proposed finger mechanism were explained, and simulation and experiments using the prototype were conducted to verify the gripping performance of the proposed finger mechanism.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.1
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• pp.111-116
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• 2010

To improve occupants' safety in an emergency, crashworthy design is necessary to rotorcraft design and development. Especially, landing gear has the important role for crashworthy design because landing gear absorbs relatively large energy for the crash landing. In addition, military specifications require failure of landing gear shall not increase danger to any occupants by penetration of the airframe. To meet the specification requirements, crashworthiness device like failure mechanism should be prepared so that landing gear is collapsed safely and doesn't penetrate the airframe. In this study, design and design development test of the failure mechanism which is necessary for the rotorcraft landing gear was performed. First, collapse scenario was determined for the landing gear not to penetrate the airframe. Then, the failure pin which is the most important part of the failure mechanism was designed with 2 strength range in order to meet design criteria. Finally, design of the failure mechanism was verified successfully by design development test.

• CELLMED
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• v.5 no.4
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• pp.27.1-27.6
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• 2015

Literatures and experimental studies have shown that Prunella has an effect on anti-hypertension, however, its components are complicated, so that it is still difficult to clear the specific roles of its various components in blood pressure regulation in. So we decide to systematically study the anti-hypertension mechanism of Prunella. We integrated multiple databases and constructed molecular interaction network between the chemical constituents of Prunella Vulgaris and hypertension based on entity grammar systems model. The network has 262 nodes and 802 edges. Then we infer the interactions between chemical compositions and disease targets to clarify the anti-hypertension mechanism. Finally, we found Prunella could influence hypertension by regulating apoptosis, cell proliferation, blood vessel development and vasoconstriction, etc. Thus this study provides reference for drug development and compatibility, and also gives guidance for health care at a certain extent.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.497-501
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• 2008

To improve occupants' safety in an emergency, crashworthy design is necessary to rotorcraft design and development. To improve crashworthiness capability, most of the crash energy should be absorbed by rotorcraft and the energy transmitted to the occupants should be minimized. To absorb the crash energy efficiently, the individual energy attenuation provided by landing gear, structure, fuel tank and seats should be considered totally. Especially, landing gear has the important role for crashworthy design because landing gear absorbs relatively large energy for the crash landing. In addition, military specifications require failure of landing gear shall not increase danger to any occupants by penetration of the airframe. To meet the specification requirements, failure mechanism should be prepared so that landing gear is collapsed safely and doesn't penetrate the airframe. In this study, design of failure mechanism which is necessary for the rotorcraft landing gear was performed and the results were presented.

• Structural Engineering and Mechanics
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• v.72 no.2
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• pp.275-291
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• 2019

In a super-large underground with "large span and high side wall", it is buried in mountains with uneven lithology, complicated geostress field and developed geological structure. These surrounding rocks are more susceptible to stability issues during the construction period. This paper takes the left bank of Baihetan hydropower station (span is 34m) as a case study example, wherein the deformation mechanism of surrounding rock appears prominent. Through analysis of geological, geophysical, construction and monitoring data, the deformation characteristics and factors are concluded. The failure mechanism, spatial distribution characteristics, and evolution mechanism are also discussed, where rock mechanics theory, $FLAC^{3D}$ numerical simulation, rock creep theory, and the theory of center point are combined. In general, huge underground cavern stability issues has arisen with respect to huge-scale and adverse geological conditions since settling these issues will have milestone significance based on the evolutionary pattern of the surrounding rock and the correlation analyses, the rational structure of the factors, and the method of nonlinear regression modeling with regard to the construction and development of hydropower engineering projects among the worldwide.

• Journal of Science Education
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• v.45 no.1
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• pp.42-54
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• 2021

In this study, we examine how scientific background is developed in order to raise the systematic strategy of scientific literate person's training, and provide the necessary foundation for the structure of future scientific literate person's training programs. For this purpose, we analyzed newspaper articles at the expert workshop of science education, discussed the true nature of scientific literate person, and derived the mechanism of manifesting scientific background. The derived mechanism was ranked in the order of understanding, empathy, execution, and sympathy. Using the presented stages and the parameters of stage transition, it is possible to construct an educational program and train the actual scientific literate person through science education when it is applied to school sites.

• Journal of the Korea Institute of Military Science and Technology
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• v.26 no.4
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• pp.313-323
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• 2023

The wearable robot system is designed to assist human skeletal and muscular systems for enhancing user's abilities in various fields, including medical, industrial, and military. The military has an expanding need for wearable robots with the integration of surveillance/control systems and advanced equipment in unstructured battlefield environments. However, there is a lack of research on the design and mechanism of wearable robots, especially for power assist systems. This study proposes a lightweight wearable robot system that provides comfortable wear and muscle support effects in various movements for soldiers performing high-strength and endurance missions. The Power assist mechanism is described and verified, and the tasks that require power assist are analyzed. This study explain the system including its driving mechanism, control system, and mechanical design. Finally, the performance of the robot is verified through experiments and evaluations, demonstrating its effectiveness in muscle support.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.1 s.94
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• pp.125-131
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• 1999

For linkage mechanisms driven by a cam, cam profile is the major design factor and is determined by the cam follower motion. If a cam mechanism has additional kinematic linkage besides cam and follower then the follower motion should be specified from the motion of end linkage member so that cam would be able to generate the desired end linkage motion. In this paper, a cam-linkage mechanism is constructed with the combinations of modular linkage elements including cam and follower and as a result, a planar cam-linkage mechanism design software with the cam profile optimization function is developed and presented.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.312-316
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• 2004

In this study, a spatial 3-dof haptic mechanism is implemented. The implemented mechanism does not employ the gear transmissions as velocity reducers for all three joints but uses wire-based transmissions, thereby it is able to minimize the frictions significantly. Also, by employing the structure of the four-bar mechanism to drive third joint from close to the base, the mechanism is able to minimize the inertia effect from the third actuator very effectively. Its kinematic analysis such as position and velocity analyses are performed first. Then, its operating software development, hardware implementation, and the related interfaces between a PC and the implemented Haptic device are completed. To evaluate its potential and its performance as a haptic device, a experiment generating a virtual constraint in a operational task space is conducted and preliminary results are discussed.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.11
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• pp.1272-1278
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• 2011

Mechanisms of the robot system should be developed according to the task. In this study, we propose improving adaptability of the robot mechanism with the modularized joint mechanism. Adaptability is the measure of the system ability to cope with change or uncertainty. Modular type joint has been widely used in development of various robots including reconfigurable robots. To build robotic systems more flexibly and quickly with low costs of manufacturing and maintenance, we have designed a modular type joint with one degree of freedom for general purpose. This module is designed to be compact, light-weight and self-controlled. In this design, we consider the kinematics and dynamics properties of the modular type joint.